Method, terminal device, base station, computer readable medium for measuring cross-link interference, and methods and apparatuses for random access preamble allocation, determination, and data transmission

ABSTRACT

A terminal device and a method for measuring cross-link interference. The method includes receiving time-frequency resource configuration information from a base station, wherein the time-frequency resource configuration information includes configuration information of measurement time-frequency resources for measuring the cross-link interference. The method also includes determining measurement time-frequency resources for measuring the cross-link interference according to the time-frequency resource configuration information. The method further includes measuring the cross-link interference on the measured time-frequency resources and feeding back the measurement result of the cross-link interference to the base station.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a division of application Ser. No. 16/792,024, nowU.S. Pat. No. 11,411,664, which is based on and claims priority under35. U.S.C. 119 to Chinese Patent Application No. 201910116881.6 filed onFeb. 14, 2019 and Chinese Patent Application No. 201910510150.X filed onJun. 13, 2019, the disclosures of which are herein incorporated byreference in their entirety.

BACKGROUND 1. Field

The present disclosure relates to the field of wireless communicationtechnologies and, more particularly, to a method, terminal device, basestation, and computer readable medium for measuring cross-linkinterference, and methods and apparatuses for random access preambleallocation, determination, and data transmission.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4th generation (4G) communication systems, efforts havebeen made to develop an improved 5th generation (5G) or pre-5Gcommunication system. The 5G or pre-5G communication system is alsocalled a ‘beyond 4G network’ or a ‘post long term evolution (LTE)system’. The 5G communication system is considered to be implemented inhigher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplishhigher data rates. To decrease propagation loss of the radio waves andincrease the transmission distance, the beamforming, massivemultiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO),array antenna, an analog beamforming, and large scale antenna techniquesare discussed with respect to 5G communication systems. In addition, in5G communication systems, development for system network improvement isunder way based on advanced small cells, cloud radio access networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul, moving network, cooperative communication,coordinated multi-points (CoMP), reception-end interference cancellationand the like.

In the 5G system, hybrid frequency shift keying (FSK) and Feher'squadrature amplitude modulation (FQAM) and sliding window superpositioncoding (SWSC) as an advanced coding modulation (ACM), and filter bankmulti carrier (FBMC), non-orthogonal multiple access (NOMA), and sparsecode multiple access (SCMA) as an advanced access technology have beendeveloped.

The Internet, which is a human centred connectivity network where humansgenerate and consume information, is now evolving to the Internet ofthings (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The Internet ofeverything (IoE), which is a combination of the IoT technology and thebig data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology”,“wired/wireless communication and network infrastructure”, “serviceinterface technology”, and “security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing information technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, MTC, and M2M communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud RAN as theabove-described big data processing technology may also be considered tobe as an example of convergence between the 5G technology and the IoTtechnology.

As described above, various services can be provided according to thedevelopment of a wireless communication system, and thus a method foreasily providing such services is required.

SUMMARY

The disclosure provides a measurement and feedback scheme for cross-linkinterference, especially for cells operating in a full-duplex mode andcells operating in a dynamic time-division duplex mode. By appropriatelyconfiguring measurement time-frequency resources and sequences andspecifying the measurement and feedback schemes, the provided solutioncan effectively reduce the impact of cross-link interference on systemperformance.

In addition, in order to overcome the problem of a long access delayexisting in the existing wireless communication technology, the presentdisclosure also provides a solution that may improve a random accesssuccess rate.

In an embodiment, there is provided a method for measuring cross-linkinterference. The method includes: receiving time-frequency resourceconfiguration information from a base station, which time-frequencyresource configuration information includes configuration information ofmeasurement time-frequency resources for measuring the cross-linkinterference; determining measurement time-frequency resources formeasuring the cross-link interference according to the time-frequencyresource configuration information; measuring the cross-linkinterference on the measurement time-frequency resources; and feedingback a measurement result of the cross-link interference to the basestation.

In an embodiment, the time-frequency resource configuration informationcomprises configuration information of reference signal time-frequencyresources configured by the base station, and determining measurementtime-frequency resources according to the time-frequency resourceconfiguration information includes determining, as the measurementtime-frequency resources, the reference signal time-frequency resourcesaccording to the configuration information of the reference signaltime-frequency resources.

In an embodiment, the time-frequency resource configuration informationcomprises information of a set of reference signal time-frequencyresources and resource index set indication information configured bythe base station, and said determining measurement time-frequencyresources according to the time-frequency resource configurationinformation includes determining reference signal time-frequencyresources for uplink sounding and the measurement time-frequencyresources for downlink measurement according to information of the setof the reference signal time-frequency resources and the resource indexset indication information.

In an embodiment, the method further includes receiving sequenceresource configuration information from the base station, wherein thesequence resource configuration information comprises at least one of:

a root sequence configuration of a used reference signal sequence,

a cyclic shift configuration, or

a comb structure configuration.

In an embodiment, said measuring the cross-link interference on themeasurement time-frequency resources includes measuring a ReferenceSignal Received Power (RSRP) according to a reference signal sequence ora set of reference signal sequences transmitted on the measurementtime-frequency resources.

In an embodiment, said measuring the cross-link interference on themeasurement time-frequency resources includes measuring received signalstrength on the measurement time-frequency resources directly.

In an embodiment, said feeding back the measurement result of thecross-link interference to the base station includes at least one of:

feeding back the measured RSRP or received signal strength directly,

feeding back a degree of impact of the measured cross-link interferenceon a Modulation Coding Scheme (MCS) level, or

feeding back an indication which indicates whether a terminal device iscapable of being scheduled to receive downlink data on the currenttime-frequency resources.

In an embodiment, the time-frequency resource configuration informationfurther includes at least one of:

periodicity information in the configuration information of referencesignal time-frequency resources,

separately configured periodicity information for the measurementtime-frequency resources, or

separately configured time configuration information for the measurementtime-frequency resources.

In an embodiment, the method further includes transmitting a downlinkmeasurement request to the base station, and wherein the time-frequencyresource configuration information and/or sequence resourceconfiguration information received from the base station is configuredby the base station in response to the downlink measurement request.

In an embodiment, the time-frequency resource configuration informationand/or sequence resource configuration information received from thebase station is semi-static.

In an embodiment, there is provided a method for determining cross-linkinterference. The method includes: configuring time-frequency resourcesfor a terminal device, which time-frequency resources comprisemeasurement time-frequency resources for measuring the cross-linkinterference; transmitting time-frequency resource configurationinformation to the terminal device; receiving, from the terminal device,a measurement result of cross-link interference measured by the terminaldevice on measurement time-frequency resources for measuring thecross-link interference determined according to the time-frequencyresource configuration information; and scheduling the terminal deviceaccording to the measurement result.

In an embodiment, said configuring time-frequency resources for aterminal device includes: configuring, as the measurement time-frequencyresources, reference signal time-frequency resources for the terminaldevice.

In an embodiment, said configuring time-frequency resources for aterminal device includes: configuring a set of reference signaltime-frequency resources and a resource index set indication for theterminal device, and wherein the set of reference signal time-frequencyresources and the resource index set indication are used to determinereference signal time-frequency resources for uplink sounding and themeasurement time-frequency resources for downlink measurement.

In an embodiment, the method further includes: configuring a sequenceresource configuration for the terminal device, and transmittingsequence resource configuration information to the terminal device, andwherein the sequence resource configuration information comprises atleast one of:

a root sequence configuration of a used reference signal sequence,

a cyclic shift configuration, or

a comb structure configuration.

In an embodiment, said receiving, from the terminal device, ameasurement result includes: receiving a Reference Signal Received Power(RSRP) measured by the terminal device according to a reference signalsequence or a set of reference signal sequences transmitted on themeasurement time-frequency resources.

In an embodiment, said receiving, from the terminal device, ameasurement result includes: receiving a received signal strengthmeasured directly by the terminal device on the measurementtime-frequency resources.

In an embodiment, the measurement result comprises at least one of:

the measured RSRP or received signal strength measured by the terminaldevice,

a degree of impact of the measured cross-link interference on ModulationCoding Scheme (MCS) level, or

an indication which indicates whether the terminal device is capable ofbeing scheduled to receive downlink data on the current time-frequencyresources.

In an embodiment, said configuring time-frequency resources for aterminal device includes at least one of:

configuring a period of reference signal time-frequency resources as aperiod of the measurement time-frequency resources,

configuring a period of the measurement time-frequency resourcesseparately, or

configuring time configuration information of the measurementtime-frequency resources separately.

In an embodiment, the method further includes: receiving a downlinkmeasurement request from the terminal device, and wherein saidconfiguring time-frequency resources and/or sequence resources for theterminal device is performed by the base station in response to thedownlink measurement request.

In an embodiment, said configuring time-frequency resources and/orsequence resources for the terminal device is performed semi-statically.

In an embodiment, there is provided a terminal device. The terminaldevice includes a processor; and a memory having stored thereincomputer-executable instructions which, when executed by the processor,cause the terminal device to execute the method according to the firstaspect of the present disclosure.

In an embodiment, there is provided a base station. The base stationincludes a processor; and a memory having stored thereincomputer-executable instructions which, when executed by the processor,cause the terminal device to execute the method according to the secondaspect of the present disclosure.

In an embodiment, there is provided computer-readable medium havingstored thereon instructions which, when executed by a processor, causethe processor to perform the method according to the first or secondaspect of the present disclosure.

In an embodiment, there is provided a random access preamble allocationmethod, which includes determining whether an interference strengthbetween adjacent cells is greater than a strength threshold; and whenthe interference strength is greater than the strength threshold,allocating, for each of the adjacent cells, an identical ZC sequencelength, an identical cyclic shift interval, an identical logical rootsequence number, and different and continuous random access preamble setindex numbers, wherein the ZC sequence length, the cyclic shiftinterval, the logical root sequence number, and the random accesspreamble set index number are configured to determine an availablerandom access preamble set of the each of the adjacent cells, andwherein the random access preamble generated from the identical logicalroot sequence number exists in the available random access preamble setcorresponding to at least two continuous random access preamble setindex numbers.

In an embodiment, a sub-carrier space corresponding to the random accesspreamble is lower than 1.25 KHz.

In an embodiment, the sub-carrier space is equal to 1 KHz, and a preguard period of the random access preamble and a cyclic prefix of therandom access preamble are located in a transmission time interval priorto the transmission time interval where the random access preamble islocated.

In an embodiment, the sub-carrier space is higher than 1 KHz and lowerthan 1.25 KHz, and a sum of lengths of following items is 1 ms: a preguard period of the random access preamble, a cyclic prefix of therandom access preamble, the random access preamble, and a post guardperiod of the random access preamble.

In an embodiment, the post guard period is zero, and a cyclic prefix ofa first orthogonal frequency division multiplexing (OFDM) symbol in atransmission time interval subsequent to the transmission time interval,where the random access preamble is located, functions as the post guardperiod of the random access preamble, or the length of the pre guardperiod is equal to the length of the cyclic prefix of the random accesspreamble, and a difference between a sum of lengths, which include thelength of the post guard period and a length of the cyclic prefix of thefirst OFDM symbol of the subsequent transmission time interval, and thelength of the cyclic prefix of the random access preamble is smallerthan or equal to 2Ts, or the length of the pre guard period is zero, anda difference between the length of the post guard period and the lengthof the cyclic prefix of the random access preamble is smaller than orequal to 2Ts.

According to a seventh aspect of the present disclosure, there isprovided a random access preamble determination method, which includes:obtaining information of a target cell, the information including a ZCsequence length, a logical root sequence number, a random accesspreamble set index number, and a cyclic shift interval; calculating aninitial logical root sequence number and an initial cyclic shift indexaccording to the obtained information; determining an available randomaccess preamble set of the target cell according to the cyclic shiftinterval, the calculated initial logical root sequence number, and thecalculated initial cyclic shift index, wherein a random access preamblegenerated from the identical logical root sequence number exists in theavailable random access preamble set corresponding to at least twocontinuous random access preamble set index numbers.

In an embodiment, the calculating the initial logical root sequencenumber and the initial cyclic shift index according to the obtainedinformation includes: calculating, according to the ZC sequence lengthand the cyclic shift interval, a number of random access preamblesgenerated from one logical root sequence number; calculating the initiallogical root sequence number, according to the logical root sequencenumber, the random access preamble set index number, and the calculatednumber of the random access preambles; and calculating the initialcyclic shift index, according to the random access preamble set indexnumber and the calculated number of the random access preambles.

In an embodiment, the determining the available random access preambleset of the target cell includes: determining, according to acorrespondence between the logical root sequence number and a physicalroot sequence number, an initial physical root sequence numbercorresponding to the initial logical root sequence number; selecting andgenerating, according to the initial physical root sequence number, arandom access preamble of which a cyclic shift amount is greater than orequal to a product of the initial cyclic shift index and the cyclicshift interval and of which the number is a predetermined number,wherein when the number of the random access preamble, of which thecyclic shift amount generated according to the initial physical rootsequence number is greater than or equal to the product of the initialcyclic shift index and the cyclic shift interval, is smaller than thepredetermined number, the logical root sequence number is increased by1; in the random access preamble corresponding to a consecutive logicalroot sequence number after being increased by 1, an additional randomaccess preamble is selected starting from the random access preamble ofwhich a cyclic shift index is smallest, in an order of the cyclic shiftindex from small to large, to be expanded into the random accesspreamble that has been selected; and operations of increasing thelogical root sequence number by 1 and selecting the random accesspreamble in the order are repeated, until the number of the selectedrandom access preamble reaches the predetermined number.

In an embodiment, there is provided a data transmission method, whichincludes: receiving scheduling information from a base station;determining whether an allocated resource indicated by the schedulinginformation from the base station includes a resource which is at leastoverlapped with a cyclic prefix of a random access preamble or therandom access preamble; obtaining indication information indicatingwhether transmission is allowed on the overlapped resource; when aresult of the determining indicates that there is the overlappedresource and the indication information indicates that the transmissionis allowed on the overlapped resource, transmitting a signal on theoverlapped resource; and when the result indicates that there is theoverlapped resource and the indication information indicates that a userequipment shall avoid the overlapped resource when transmitting thesignal, avoiding the overlapped resource when transmitting the signal,wherein a sub-carrier space corresponding to the random access preambleis equal to or smaller than 1 KHz, and at least the cyclic prefix of therandom access preamble or the random access preamble is located in atransmission time interval prior to the transmission time interval wherethe random access preamble is located.

In an embodiment, there is provided a system of a storage deviceincluding at least one computing device and at least one storage devicestoring an instruction, wherein when the instruction is operated by theat least one computing device, the at least one computing device isenabled to perform the method according to any of the fifth to eighthaspects of the present disclosure.

In an embodiment, there is provided a computer readable storage mediumfor storing an instruction, wherein when the instruction is operated byat least one computing device, the at least one computing device isenabled to perform the method according to any of the fifth to eighthaspects of the present disclosure.

In an embodiment, there is provided a random access preamble allocationapparatus, which includes: an interference strength determining unit,which determines whether an interference strength between adjacent cellsis greater than a strength threshold; and an index number allocatingunit, which allocates, for each of the adjacent cells, an identical ZCsequence length, an identical cyclic shift interval, an identicallogical root sequence number, and different and continuous random accesspreamble set index numbers, when the interference strength is greaterthan the strength threshold, wherein the ZC sequence length, the cyclicshift interval, the logical root sequence number, and the random accesspreamble set index number are configured to determine an availablerandom access preamble set of the each of the adjacent cells, andwherein the random access preamble generated from the identical logicalroot sequence number exists in the available random access preamble setcorresponding to at least two continuous random access preamble setindex numbers.

In an embodiment, a sub-carrier space corresponding to the random accesspreamble is lower than 1.25 KHz.

In an embodiment, the sub-carrier space is equal to 1 KHz, and a preguard period of the random access preamble and a cyclic prefix of therandom access preamble are located in a transmission time interval priorto the transmission time interval where the random access preamble islocated.

In an embodiment, the sub-carrier space is higher than 1 KHz and lowerthan 1.25 KHz, and a sum of lengths of following items is 1 ms: a preguard period of the random access preamble, a cyclic prefix of therandom access preamble, the random access preamble, and a post guardperiod of the random access preamble.

In an embodiment, the post guard period is zero, and a cyclic prefix ofa first orthogonal frequency division multiplexing (OFDM) symbol in atransmission time interval subsequent to the transmission time interval,where the random access preamble is located, functions as the post guardperiod of the random access preamble, or, the length of the pre guardperiod is equal to the length of the cyclic prefix of the random accesspreamble, and a difference between a sum of lengths, which include thelength of the post guard period and a length of the cyclic prefix of thefirst OFDM symbol of the subsequent transmission time interval, and thelength of the cyclic prefix of the random access preamble is smallerthan or equal to 2Ts, or, the length of the pre guard period is zero,and a difference between the length of the post guard period and thelength of the cyclic prefix of the random access preamble is smallerthan or equal to 2Ts.

In an embodiment, there is provided a random access preambledetermination apparatus, which includes: an information obtaining unit,which obtains information of a target cell, the information including aZC sequence length, a logical root sequence number, a random accesspreamble set index number, and a the cyclic shift interval; acalculating unit, which calculates an initial logical root sequencenumber and an initial cyclic shift index according to the obtainedinformation; and a random access preamble set determining unit, whichdetermines an available random access preamble set of the target cellaccording to the cyclic shift interval, the calculated initial logicalroot sequence number, and the calculated initial cyclic shift index,wherein a random access preamble generated from the identical logicalroot sequence number exists in the available random access preamble setcorresponding to at least two continuous random access preamble setindex numbers.

In an embodiment, the calculating unit is configured to: calculate,according to the ZC sequence length and the cyclic shift interval, anumber of random access preambles generated from one logical rootsequence number; calculate the initial logical root sequence number,according to the logical root sequence number, the random accesspreamble set index number, and the calculated number of the randomaccess preambles; and calculate the initial cyclic shift index,according to the random access preamble set index number and thecalculated number of the random access preambles.

In an embodiment, the random access preamble set determining unit isconfigured to: determine, according to a correspondence between thelogical root sequence number and a physical root sequence number, aninitial physical root sequence number corresponding to the initiallogical root sequence number; and select and generate, according to theinitial physical root sequence number, a random access preamble of whicha cyclic shift amount is greater than or equal to a product of theinitial cyclic shift index and the cyclic shift interval and of whichthe number is a predetermined number, wherein when the number of therandom access preamble, of which the cyclic shift amount generatedaccording to the initial physical root sequence number is greater thanor equal to the product of the initial cyclic shift index and the cyclicshift interval, is smaller than the predetermined number, the logicalroot sequence number is increased by 1; in the random access preamblecorresponding to a consecutive logical root sequence number after beingincreased by 1, an additional random access preamble is selectedstarting from the random access preamble of which a cyclic shift indexis smallest, in an order of the cyclic shift index from small to large,to be expanded into the random access preamble that has been selected;and operations of increasing the logical root sequence number by 1 andselecting the random access preamble in the order are repeated, untilthe number of the selected random access preamble reaches thepredetermined number.

In an embodiment, there is provided a data transmission apparatus, whichincludes: a scheduling information receiving unit, which receivesscheduling information from a base station; a determining unit, whichdetermines whether an allocated resource indicated by the schedulinginformation from the base station includes a resource which is at leastoverlapped with a cyclic prefix of a random access preamble or therandom access preamble; an indication information obtaining unit, whichobtains indication information indicating whether transmission isallowed on the overlapped resource; a data transmitting unit, whichtransmits a signal on the overlapped resource, when a result of thedetermination indicates that there is the overlapped resource and theindication information indicates that the transmission is allowed on theoverlapped resource, and avoids the overlapped resource whentransmitting the signal, when the result indicates that there is theoverlapped resource and the indication information indicates that a userequipment shall avoid the overlapped resource when transmitting thesignal, wherein a sub-carrier space corresponding to the random accesspreamble is equal to or smaller than 1 KHz, and at least the cyclicprefix of the random access preamble or the random access preamble islocated in a transmission time interval prior to the transmission timeinterval where the random access preamble is located.

According to a fourteenth aspect of the present disclosure, there isprovided a physical random access channel, which includes: a randomaccess preamble and a cyclic prefix of the random access preamble,wherein a sub-carrier space corresponding to the random access preambleis lower than 1.25 KHz.

In an embodiment, the sub-carrier space is equal to 1 KHz, and thephysical random access channel includes a pre guard period, and therandom access preamble and a cyclic prefix of the random access preambleare located in a transmission time interval prior to the transmissiontime interval where the random access preamble is located.

In an embodiment, the sub-carrier space is higher than 1 KHz and lowerthan 1.25 KHz, and the physical random access channel includes a preguard period and a post guard period, and a sum of lengths of followingitems is 1 ms: the pre guard period of the random access preamble, thecyclic prefix of the random access preamble, the random access preamble,and the post guard period of the random access preamble.

In an embodiment, a length of the post guard period is zero, and acyclic prefix of a first OFDM symbol in a transmission time intervalsubsequent to the transmission time interval, where the random accesspreamble is located, functions as the post guard period of the randomaccess preamble, or, the length of the pre guard period is equal to thelength of the cyclic prefix of the random access preamble, and adifference between a sum of lengths, which include the length of thepost guard period and a length of the cyclic prefix of the first OFDMsymbol of the subsequent transmission time interval, and the length ofthe cyclic prefix of the random access preamble is smaller than or equalto 2Ts, or, the length of the pre guard period is zero, and a differencebetween the length of the post guard period and the length of the cyclicprefix of the random access preamble is smaller than or equal to 2Ts.

According to the embodiment of the present disclosure, when thesub-carrier space corresponding to the random access preamble is lowerthan 1.25 KHz, the length of the random access preamble may beincreased, and the number of orthogonal random access preambles may alsobe increased, so as to improve a detection success rate of the randomaccess preamble. According to another embodiment of the presentdisclosure, the random access preambles generated from the identicallogical root sequence number are enabled to exist in the availablerandom access preamble set corresponding to at least two continuousrandom access preamble set index numbers, so as to be also possible toincrease the number of the orthogonal random access preambles. Accordingto the present disclosure, when performing a downlink signaltransmission on a random access resource, interferences, which come fromthe random access preamble of the present cell, the random accesspreamble of the adjacent cell, and the downlink signal of the adjacentcell, and which are performed on the random access preamble itself, maybe reduced, and the interference from the random access preamble onuplink and downlink data transmission of the present cell may also bereduced, so that a success rate of a random access of a terminal may beimproved.

Additional aspects and/or advantages of a general concept of the presentdisclosure will be stated in the following descriptions in part, andanother part will be clear through the descriptions, or may be knownthrough implementation of the general concept of the present disclosure.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document: the terms “include” and “comprise,” aswell as derivatives thereof, mean inclusion without limitation; the term“or,” is inclusive, meaning and/or; the phrases “associated with” and“associated therewith,” as well as derivatives thereof, may mean toinclude, be included within, interconnect with, contain, be containedwithin, connect to or with, couple to or with, be communicable with,cooperate with, interleave, juxtapose, be proximate to, be bound to orwith, have, have a property of, or the like; and the term “controller”means any device, system or part thereof that controls at least oneoperation, such a device may be implemented in hardware, firmware orsoftware, or some combination of at least two of the same. It should benoted that the functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for certain words and phrases are provided throughout thispatent document, those of ordinary skill in the art should understandthat in many, if not most instances, such definitions apply to prior, aswell as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 schematically illustrates a diagram of inter-cell cross-linkinterference according to an embodiment of the present disclosure;

FIG. 2 schematically shows a diagram of cross-link interference in acell according to an embodiment of the present disclosure;

FIG. 3 schematically illustrates a flowchart of a method for measuringcross-link interference performed at a terminal device according to anembodiment of the present disclosure;

FIG. 4 schematically illustrates a diagram of a time-frequency resourceconfiguration according to an embodiment of the present disclosure;

FIG. 5 schematically illustrates a diagram of a comb structuremeasurement according to an embodiment of the present disclosure;

FIG. 6 schematically illustrates a measurement of a plurality ofthresholds according to an embodiment of the present disclosure;

FIG. 7 schematically illustrates an aperiodic measurement and feedbackmanner according to an embodiment of the present disclosure;

FIG. 8 schematically illustrates a flowchart of a method for determiningcross-link interference performed at a base station according to anembodiment of the present disclosure;

FIG. 9 schematically illustrates a diagram of measuring cross-linkinterference of different terminal devices according to an embodiment ofthe present disclosure;

FIG. 10 schematically illustrates a configuration manner of downlinkmeasurement time-frequency resources according to an embodiment of thepresent disclosure;

FIG. 11 schematically illustrates a structural block diagram of aterminal device according to an embodiment of the present disclosure;

FIG. 12 schematically illustrates a structural block diagram of a basestation according to an embodiment of the present disclosure;

FIG. 13 illustrates a diagram of at least one portion of a frameincluding a random access preamble according to an exemplary of thepresent disclosure;

FIG. 14 illustrates a diagram of a physical random access channelaccording to an exemplary of the present disclosure;

FIGS. 15-17 illustrate diagrams of an interference caused by resourceoverlap according to an embodiment of the present disclosure;

FIG. 18 illustrates a flow diagram of a data transmission methodaccording to an embodiment of the present disclosure;

FIG. 19 illustrates a flow diagram of a random access preambleallocation method according to an embodiment of the present disclosure;

FIG. 20 illustrates a diagram of allocating a random access preamble setindex number according to an embodiment of the present disclosure;

FIG. 21 illustrates a diagram of an interference situation of a randomaccess preamble among cells according to an embodiment of the presentdisclosure;

FIG. 22 illustrates a diagram of restraining an inter-cell interferenceaccording to an embodiment of the present disclosure;

FIG. 23 illustrates a flow diagram of a random access preambledetermination method according to an embodiment of the presentdisclosure;

FIG. 24 illustrates a diagram of grouping random access preamblesaccording to an embodiment of the present disclosure;

FIG. 25 illustrates a block diagram of a data transmission apparatusaccording to an embodiment of the present disclosure;

FIG. 26 illustrates a block diagram of a random access preambleallocation apparatus according to an embodiment of the presentdisclosure;

FIG. 27 illustrates a block diagram of an apparatus for determining arandom access preamble according to an embodiment of the presentdisclosure;

FIG. 28 illustrates a terminal device according to embodiments of thepresent disclosure; and

FIG. 29 schematically illustrates a base station according toembodiments of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 29 , discussed below, and the various embodiments usedto describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

Embodiments of the present disclosure are described in detail below,examples of which are illustrated in the accompanying drawings, in whichthe same or similar reference numbers denote the same or similarelements or elements having the same or similar functions throughout.The embodiments described below with reference to the drawings are forexplaining the present disclosure only, and should not be construed aslimiting the present disclosure.

It will be understood by the skilled in the art that singular forms “a”,“an”, “said” and “the” used herein may also include plural forms, unlessspecifically stated. It should be further understood that the word“comprising” used in the description of the present disclosure refers topresence of features, integers, steps, operations, elements, and/orcomponents, but does not exclude presence or addition of one or moreother features, Integers, steps, operations, elements, components,and/or combinations thereof. It should be understood that when anelement is referred to as being “connected” or “coupled” to anotherelement, it can be directly connected or coupled to the other element,or there may also be intermediate elements. In addition, “connected” or“coupled” as used herein may include wirelessly connected or wirelesslycoupled. As used herein, the phrase “and/or” includes all or any of oneor more of associated listed items, and all of combinations thereof.

It may be understood by the skilled in the art that, unless definedotherwise, all terms (including technical and scientific terms) usedherein have the same meaning as commonly understood by the skilled inthe art to which the present disclosure belongs. It should also beunderstood that the terms such as those defined in a general dictionaryshould be understood as having a meaning that is consistent with that inthe context of the prior art, and will not be explained with anidealized or too formal meaning, unless specifically defined herein.

The skilled in the art may understand that the “terminal” and “terminaldevice” used herein include not only a wireless signal receiver device,which is a device only having a wireless signal receiver without atransmitting capability, but also a device with receiving andtransmitting hardware, which is a device having receiving andtransmitting hardware capable of performing a bidirectionalcommunication over a bidirectional communication link. Such a device mayinclude: a cellular or other communication device having a single linedisplay or a multi-line display or a cellular or other communicationdevice without a multi-line display; a Personal Communication Service(PCS), which may combine voice, data processing, fax and/or datacommunication capabilities; a Personal Digital Assistant (PDA), whichmay include a Radio Frequency (RF) receiver, a pager, Internet/Intranetaccess, a web browser, a notepad, a calendar, and/or a GlobalPositioning System (GPS) receiver; a conventional laptop and/or palmtopcomputer or other device, which may be a conventional laptop and/orpalmtop computer or other device having and/or including an RF receiver.The “terminal”, “terminal device” as used herein may be portable,transportable, installed in a vehicle (of aviation, maritime, and/orland), or may be adapted and/or configured to operate locally, and/ormay operate in a distributed form on the earth and/or at any otherlocations in space. The “terminal” and “terminal device” used herein mayalso be a communication terminal, an Internet terminal, a music/videoplaying terminal, such as a PDA, a Mobile Internet Device (MID), and/ora mobile phone having a music/video playback function, or a smart TV, aset-top box and other devices.

Generally, the present disclosure provides a method for measuring andfeeding back cross-link interference, which is suitable for ahalf-duplex terminal device operating in a cell served by a full-duplexbase station. The terminal device may perform the following operations:receiving measurement time-frequency resource configuration informationtransmitted from the base station; measuring cross-link interferenceaccording to the measurement time-frequency resources configured by thebase station; feeding back the measurement result of the cross-linkinterference to the base station; and receiving scheduling of the basestation information.

In addition, the present disclosure provides a method for determiningcross-link interference, which is suitable for a system operating indynamic time division duplex mode, in which a target base station mayperform the following operations: configuring measurement time-frequencyresources according to time slot transmission direction of the localcell and the neighboring cell; transmitting measurement time-frequencyresource configuration information to the terminal device; receiving ameasurement result fed back by the terminal device; and transmitting themeasurement result to the interfering base station.

Correspondingly, the downlink terminal device served by the target basestation may perform the following operations: receiving measurementtime-frequency resource configuration information transmitted from thebase station; measuring cross-link interference according to themeasurement time-frequency resources configured by the base station; andfeeding back a measurement result of cross-link interference.

The interfering base station may perform the following operations:receiving the measurement result transmitted by the target base station;and transmitting scheduling information to the interfering terminaldevice.

In order to make the purpose, technical means, and advantages of thepresent application clearer, the present application is furtherdescribed in detail below with reference to the accompanying drawings.

FIG. 1 schematically illustrates a diagram of inter-cell cross-linkinterference according to an embodiment of the present disclosure. FIG.2 schematically shows a diagram of cross-link interference in a cellaccording to an embodiment of the present disclosure.

As estimated by ITU, the global monthly mobile data traffic will reach62 exabytes (EB, 1 EB=230 GB) by 2020, and from 2020 to 2030, the globalmobile data service will even grow at a rate of about 55% per year. Inaddition, the proportion of video services and machine and machinecommunication services in mobile data services will gradually increase.In 2030, video services will be five times more than non-video services,while machine and machine communication services will account for about12% of mobile data services (See, “IMT traffic estimates for the years2020 to 2030, Report ITU-R M.2370-0”).

The rapid growth of mobile data services, especially the exponentialgrowth of high-definition video and ultra-high-definition videoservices, puts higher demands on the transmission rate of wirelesscommunications. In order to meet the growing demand of mobile services,it needs to propose new technologies based on 4G or 5G to furtherimprove the transmission rate and throughput of wireless communicationsystems.

Improvements to the duplex technologies are an important means offurther increasing the transmission rate and throughput of wirelesscommunication systems. The duplex technologies used in existing systemsand protocols, including Frequency Division Multiplexing (FDM) and TimeDivision Multiplexing (TDM), cannot fully utilize the availabletime-frequency resources, with the resource utilization efficiency lessthan 50%.

One possible improvement is to flexibly change the transmissiondirection (uplink or downlink) of each time slot according to factorssuch as traffic data or demand, which is referred to as Dynamic TimeDivision Duplex (Dynamic TDD) technology. By configuring thetransmission direction of a time slot in a semi-static or dynamicmanner, the flexibility of time-frequency resource configuration can beimproved, thereby improving the performance of the system.

Another possible improvement is to use a full-duplex technology. Unliketraditional half-duplex systems, which use time domain (time divisionduplexing, TDD) or frequency domain (frequency division duplexing, FDD)orthogonal segmentation for uplink and downlink, full-duplex systemsallow simultaneous transmission of users' uplink and downlink in thetime domain and in the frequency domain. Therefore, a full-duplex systemcan theoretically achieve twice the throughput of a half-duplex system.However, since the uplink and downlink are simultaneous and at the samefrequency, the transmission signal of the full-duplex system will havestrong self-interference on the received signal, and theself-interference signal will be more than 120 dB higher than the noisefloor. Therefore, in order for a full-duplex system to work, the coreissue is to design a solution to eliminate the self-interference andreduce the strength of the self-interference signal to at least the samelevel as the noise floor.

Whether it is dynamic time division duplex or full duplex, there is aproblem of cross-link interference. For the dynamic time divisionduplex, cross-link interference mainly occurs between cells. As shown inFIG. 1 , if the neighboring cells are configured with differentuplink/downlink transmission directions, for users at the edge of thecells, when a use receives downlink data transmitted by its own basestation in a downlink time slot, it will be interfered by uplink datatransmitted from users at the edge of the neighbor cell on the uplink,resulting in cross-link interference.

For the full-duplex technology, cross-link interference also exists inthe cell. For example, for a full-duplex base station serving ahalf-duplex user, it receives uplink data while transmitting downlinkdata. At this time, a user who transmits the uplink data will causecross-link interference to a user who receives the downlink data, asshown in FIG. 2 .

An effective solution to the aforementioned cross-link interference isdesired.

In addition, the full-duplex technology may further improve a spectrumuse rate on the basis of the existing wireless communication system, anddifferent from the TDD or FDD adopted in the uplink and the downlink bythe traditional half-duplex system, the full-duplex technology allowssimultaneous transmission of the uplink and downlink in a time domainand a frequency domain. Therefore, the throughput of the full-duplexsystem may reach two times of that of the half-duplex system in theory.As for a small cell and a macro cell, a radius of the macro cell islarger; in order to ensure coverage, it needs a base station to increaseemission power; and when a full-duplex communication is configured inthe macro cell, it needs to further increase the emission power toeliminate self-interference. Since the increased power will affect datatransmission and a random access procedure, a current full-duplextechnology is not applicable to the macro cell, and is only applicableto the small cell having a smaller radius relative to the macro cell.

A study with respect to the full-duplex system includes reducing accessdelay, to allow a terminal to access to a cell with a shorter delay. Asfor the small cell having a smaller radius, types and strengths ofinterferences within and among the cells will be increased when afull-duplex communication is adopted, and for example, a random accesspreamble transmitted by the terminal may be interfered by a downlinksignal of the present cell and a downlink signal of a neighboring cell.Due to the increasing of the types and strengths of the interferences, arandom access success rate of the terminal in the cell which supportsthe full-duplex communication may be affected, and when an initialrandom access fails, the terminal may initiate a random access againafter a period of time, resulting in that an access time delay willbecome large, and a transmitting power of the random access preamblewill make an interference on transmitting of the random access preambleof another terminal. Therefore, improving the random access success rateof the full-duplex system is be considered by the full-duplex system.

A method of improving the random access success rate of the full-duplexsystem includes designing a resource for a random access as a one-wayresource, that is to say, any downlink signal transmission of thepresent cell and an adjacent cell thereof is forbidden on a resourcetransmitting the random access preamble. However, the method will causea low resource usage rate.

Therefore, there is also a need of a method which may improve the randomaccess success rate.

Hereinafter, a method for measuring cross-link interference performed ata terminal device according to an embodiment of the present disclosurewill be described with reference to FIG. 3 .

FIG. 3 schematically illustrates a flowchart of a method for measuringcross-link interference performed at a terminal device according to anembodiment of the present disclosure.

In this embodiment, there is provided a method for reducing cross-linkinterference in a cell generated between terminal devices havingopposite transmission directions that are served on the sametime-frequency resources in the same cell. In the method, the basestation configures reference signal resources (including referencesignal time-frequency resources and/or reference signal sequenceresources) for the uplink terminal device (that is, the terminal deviceperforming uplink transmission); meanwhile, the base station configuresmeasurement resources (including time-frequency resources formeasurement and/or sequence resources for measurement) for the downlinkterminal device (that is, the terminal device performing downlinktransmission), where all available reference signal time-frequencyresources configured for the uplink terminal device and all availablemeasurement time-frequency resources configured for the downlinkterminal device overlap each other. The uplink reference signaltime-frequency resources configured for a single terminal device are asubset of all available reference signal time-frequency resources; thedownlink measurement time-frequency resources configured for a singleterminal device are a subset of all available measurement time-frequencyresources. The above configuration is shown in FIG. 4 .

FIG. 4 schematically illustrates a diagram of a time-frequency resourceconfiguration according to an embodiment of the present disclosure.

It should be noted that in the example shown in FIG. 4 , the uplinkreference signal time-frequency resources and the downlink measurementtime-frequency resources may be allocated to different terminal devices.

As shown in FIG. 3 , a method 300 for reducing cross-link interferenceperformed at a terminal device according to an embodiment of the presentdisclosure may include steps S301 to S304.

In step S301, the terminal device may receive time-frequency resourceconfiguration information from the base station.

Here, the time-frequency resource configuration information may includeconfiguration information of the measurement time-frequency resourcesfor measuring the cross-link interference.

Alternatively, or additionally, the terminal device may receive thesequence resource configuration information from the base station.

Here, the sequence resource configuration information may include atleast one of: a root sequence configuration of a used reference signalsequence, a cyclic shift configuration, or a comb structureconfiguration, which will be described in detail later.

In step S302, the terminal device may determine measurementtime-frequency resources for measuring the cross-link interferenceaccording to the time-frequency resource configuration information.

In an embodiment, the measurement time-frequency resources may be uplinkreference signal (e.g., uplink sounding reference signal, SRS)time-frequency resources configured by the base station, that is, theuplink reference signal time-frequency resources are used as measurementtime-frequency resources of a downlink terminal device.

Considering that the base station operating in full-duplex mode has thesame uplink and downlink time-frequency resources, and the uplink anddownlink physical resource block indexed by the same physical resourceblock have the same frequency domain positions, it directly configuresthe reference signal time-frequency resources configured for the uplinkterminal device for the downlink terminal device to measure cross-linkinterference.

If this method is used, the time-frequency resource configurationinformation received in step S301 may include configuration informationof the reference signal time-frequency resources configured by the basestation. Accordingly, step S302 may include: the terminal devicedetermines, as the measurement time-frequency resources, the referencesignal time-frequency resources according to the configurationinformation of the reference signal time-frequency resources.

In an embodiment, the terminal device may read system information orreference signal time-frequency resource configuration informationconfigured in the downlink control channel; and determine a position ofthe measurement time-frequency resources according to the configuredreference signal time-frequency resource configuration information.

The reference signal time-frequency resources are configuredperiodically, and their periodicity indication is located in theconfiguration information of the reference signal time-frequencyresources. The measurement time-frequency resources for downlinkmeasurement may also be periodically configured. The base station mayperiodically configure the measurement time-frequency resources fordownlink measurement in the following manner:

1.a Use the period configuration in the reference signal time-frequencyresource configuration information. In this way, all configurationinformation for the measurement time-frequency resources usestime-frequency resource configuration information of a reference signal.

1.b Configure the period of the measurement time-frequency resourcesseparately. In this method, the frequency domain resources use thefrequency domain configuration information of the reference signal, andthe time slot offset in the time domain resource configurationinformation uses the time-frequency resource configuration of thereference signal, and the period configuration information usesdedicated downlink measurement cycle configuration information. Theperiod configuration information may be configured in system informationor may be configured in a downlink control channel.

1.c Configure the time domain configuration information for themeasurement time-frequency resources separately. In this manner, onlythe frequency domain resources use the frequency domain configurationinformation of the reference signal, and the time domain resources aredetermined based on the separately configured time domain configurationinformation for the measurement time frequency resources. The timedomain configuration information includes a slot offset configurationand a period configuration. The time domain configuration informationcan be configured in system information or in a downlink controlchannel.

Among the foregoing manners, the configuration information of manner 1.ais the least, but the configuration flexibility is the lowest. Manner1.c can improve the configuration flexibility by using a separate timedomain resource configuration while multiplexing a part of the referencesignal resource configuration. The signaling overhead and configurationflexibility of Manner 1.b is between 1.a and 1.c.

Accordingly, the time-frequency resource configuration informationreceived by the terminal device may comprise at least one of:

periodicity information in configuration information of the referencesignal time-frequency resources,

separately configured periodicity information for the measurementtime-frequency resources, or

separately configured time configuration information for the measurementtime-frequency resources.

In another embodiment, the base station may configure a plurality ofreference signal time-frequency resources for the terminal device, andindicate a reference signal resource index for downlink measurement anda reference signal resource index for uplink sounding to be used by theterminal device. The plurality of reference signal resources (that is, aset of reference signal resources) configured by the base station areconfigured and notified in system information or downlink controlchannels; the resource index set indicate used to indicate resources tothe terminal device is configured and notified in system information ordownlink control channels.

In this way, the time-frequency resource configuration information mayinclude information of a set of reference signal time-frequencyresources and resource index set indication information configured bythe base station.

In this embodiment, step S302 may include: determining reference signaltime-frequency resources for uplink sounding and the measurementtime-frequency resources for downlink measurement according toinformation of the set of the reference signal resources and theresource index set indication information.

In an embodiment, the measurement time-frequency resources of thedownlink terminal device may be determined according to the followingmanner:

reading the system configuration information to obtain the referencesignal resource set information;

reading the resource index set indication information to determine thereference signal time-frequency resources for uplink sounding and thereference signal time-frequency resources for downlink measurement.

The resource index set may be configured in the following ways:

2.a The resource index set indication information indicates referencesignal resources for uplink sounding, and the remaining reference signalresources are used for downlink measurement. For example, the maximumnumber of available reference signal resources S_(MAX) is configured andnotified in the reference signal resource set configuration. Theresource index set indication information indicates the number ofreference signal resources S_(UL) for uplink sounding. After acquiringthe reference signal resource set configuration information and theresource index set indication information, the terminal device can knowthat the reference signal resource indexes for uplink sounding are1˜S_(UL), and the reference signal resource indexes for downlinkmeasurement are S_(UL)+1˜S_(MAX). If S_(UL)=S_(MAX), the terminal deviceis configured with no reference signal resource for downlinkmeasurement.

2.b The resource index set indication information indicates referencesignal resources for downlink measurement, and the remaining referencesignal resources are used for uplink sounding. For example, the maximumnumber of available reference signal resources S_(MAX) is configured andnotified in the reference signal resource set configuration. Theresource index set indication information indicates the number ofreference signal resources S_(DL) for downlink measurement. Afteracquiring the reference signal resource set configuration informationand the resource index set indication information, the terminal devicecan know that the reference signal resource indexes for downlinkmeasurement are 1˜S_(DL), and the reference signal resource indexes foruplink sounding are S_(DL)+1˜S_(MAX).

2.c The resource index set indication information indicates the numberof reference signal resources for uplink sounding and the number ofreference signal resources for downlink measurement. After acquiring theindication information, the terminal device can obtain reference signalresource indexes for uplink sounding and reference signal resourceindexes for downlink measurement.

2.d The resource index set indication information indicates a referencesignal resource termination index for uplink sounding and a referencesignal resource termination index for downlink measurement. Afteracquiring the resource index set indication information, the terminaldevice can obtain the reference signal resource index for uplinksounding and the reference signal resource index for downlinkmeasurement through the termination indexes.

For example, one possible manner is that if the resource index setindication information obtained by the terminal device from theconfiguration information includes a reference signal resourcetermination index I_(UL) for uplink sounding and a reference signalresource termination index I_(DL) for downlink measurement, andI_(UL)<I_(DL), the reference signal resource indexes for uplink soundingare 1˜I_(UL), and the reference signal resource indexes for downlinkmeasurement are I_(UL)+1˜I_(DL).

In this embodiment, similar to the previous embodiment, thetime-frequency resource configuration information also includes at leastone of:

periodicity information in the configuration information of thereference signal time-frequency resources,

separately configured periodicity information for the measurementtime-frequency resources, or

separately configured time configuration information for the measurementtime-frequency resources.

In another embodiment, the base station may configure time-frequencyresources for downlink measurement in the system information or thedownlink control channel. The configuration information includes afrequency-domain starting physical resource block index,frequency-domain bandwidth configuration information for configuring abandwidth of the measurement time-frequency resources, time-domain slotoffset configuration information, time-domain starting symbolconfiguration information, time-domain period configuration informationand time domain symbol number configuration information.

After receiving the above information, the terminal device knows thetime-frequency resources for downlink measurement.

After the terminal device knows the downlink time-frequency resourcesfor measurement, it can measure the cross-link interference on themeasurement time-frequency resources in step S303. Specifically, stepS303 may include:

When the terminal device receives the sequence resource configurationinformation, it measures and obtains a Reference Signal Received Power(RSRP) according to a reference signal sequence or a reference signalsequence set transmitted on the measurement time-frequency resource;

When the terminal device fails to receive the sequence resourceconfiguration information, it directly measures the received signalstrength on the measurement time-frequency resources.

For the foregoing implementation in which the uplink reference signaltime-frequency resources are used as the downlink measurementtime-frequency resources, if the foregoing manners of multiplexing orpartially multiplexing reference signal time-frequency resources areused, the configured reference signal sequence resources may be used.That is, the terminal device reads the reference signal sequenceresources configured for the terminal device, and the configurationinformation of the reference signal sequence resources may include atleast one of: a root sequence configuration of the used reference signalsequence, a cyclic shift configuration, a comb structural configuration,and so on.

In this embodiment, the terminal device reads the sequence configurationof the reference signal, so as to obtain the sequence configuration fordownlink measurement. If a plurality of reference sequences areconfigured on the same time-frequency resources, and the plurality ofreference sequences are distinguished by cyclic shift, comb structure,etc., the terminal device measures the plurality of reference sequences,respectively, to obtain RSRPs of the plurality of reference sequences.

In another embodiment, the terminal device knows part of the referencesequence configuration. The base station configures part of sequenceinformation for downlink measurement in the configuration information orsystem information. For example, the base station configures combstructure configuration information of a sequence for downlinkmeasurement in the configuration information or system information.According to the comb structure configuration information, the terminaldevice measures each comb structure, and obtains a measurement result ofthe received power of each comb structure. This process is shown in FIG.5 .

FIG. 5 schematically illustrates a diagram of a comb structuremeasurement according to an embodiment of the present disclosure.

In this embodiment, several different reference signals may use the samecomb structure. At this time, when the terminal device measures aconfigured comb structure, it measures the sum of power of the severalreference sequences using the same comb structure. A simple example isas following. The uplink reference signal configuration transmitted onthe same time-frequency resources includes: comb structure configuration1 and comb structure configuration 2, and each comb structure isconfigured with 2 different cyclic shift configurations. In thisconfiguration, four reference signal sequences are configured on thesame time-frequency resources. When the terminal device acquires theconfiguration information for the downlink measurement, it acquires thecomb structure configuration in addition to the time-frequency resourceconfiguration for the downlink measurement. The terminal device obtainsthe received power of the comb structure configuration 1 and thereceived power of the comb structure configuration 2 according to thetime-frequency resource information and the comb structureconfiguration, as shown in FIG. 5 .

In the case that the terminal device does not receive the sequenceresource configuration information, that is, only the measurementtime-frequency resource configuration information for downlinkmeasurement is received, and the reference signal sequence resourceconfiguration information is not received, the terminal device does notknow the reference sequence resource configuration. At this time, theterminal device only measures the measurement time-frequency resourcesconfigured by the base station for downlink measurement and obtains thetransmission power on the time-frequency resources.

In step S304, the terminal device feeds back the measurement result ofthe cross-link interference to the base station for further schedulingby the base station.

The feeding back the measurement result of the cross-link interferenceto the base station may include at least one of:

feeding back the measured RSRP or received signal strength directly,

feeding back the degree of impact of the measured cross-linkinterference on a Modulation Coding Scheme (MCS) level, or

feeding back an indication which indicates whether a terminal device iscapable of being scheduled to receive downlink data on the currenttime-frequency resources.

Each will be described in detail below.

1. Feeding back the measured RSRP or received signal strength directly.

In this method, different feedback amounts are used for feedbackaccording to the configuration of the downlink measurementtime-frequency resources and of the sequence.

For example, if the reference signal sequence is directly configured,the possible feedback manners include:

1.a For each configured reference signal sequence, the measured RSRP ofeach reference signal sequence is fed back. When feeding back the RSRP,the quantized measurement value can be directly fed back, or an indexcorresponding to the measurement value can be fed back according to apre-configured lookup table.

1.b The threshold is set in advance, and only the measurement valuecorresponding to the reference signal sequence above the threshold isfed back. Or, only the index value of the reference signal sequenceabove the threshold is fed back.

1.c A bitmap sequence corresponding to the reference signal sequence isfed back. The number of bits in the bitmap sequence is the configurednumber of sequences. If the measured RSRP of the corresponding indexedreference sequence is higher than the threshold, the bit in the phaseposition in the bitmap sequence is set to A; if the measured RSRP of theindexed reference sequence is lower than the threshold, the bit of thephase position in the bitmap sequence is set to B. Among them, A is bit1 or bit 0, and B is bit 0 or bit 1.

Similarly, multiple thresholds can be set in advance and a feedbacksequence corresponding to the reference signal can be fed back. Thelength of the sequence is the same as the number of the configuredreference sequences, and the value range of each element in the sequenceis related to the number of the preset thresholds. For example, if thenumber of the preset thresholds is N, the value range of each element inthe feedback sequence is 0-N. The terminal device determines the valueof the respective element according to a comparison between thecorresponding reference signal sequence and the preset thresholds.

A simple example is shown in FIG. 6 .

FIG. 6 schematically illustrates a measurement of a plurality ofthresholds according to an embodiment of the present disclosure.

In FIG. 6 , the value of the element in the feedback sequencecorresponding to the m-th sequence is determined by comparing the RSRPmeasured on the reference signal having an index of m with the presetthresholds. The RSRP falls between the threshold n-1 and the thresholdn, so the value of the corresponding element in the feedback sequence isn.

If measurement time-frequency resources and comb structures areconfigured, possible feedback manners include:

1.d The corresponding received power measurement value is fed back foreach comb structure. The quantized value of the corresponding receivedpower measurement value can be directly fed back, or the indexcorresponding to the measured value can be fed back according to apreset lookup table.

1.e A threshold is set in advance, and only the configuration index ofthe comb structure that has a received power measurement value higherthan the threshold is fed back, or the received power measurement valueof the corresponding comb structure is fed back.

1.f The corresponding bitmap sequence or feedback sequence is fed back,similar to manner 1.c.

If only time-frequency resources are configured, the possible feedbackmanners include:

1.g The received power measurement value of the time-frequency resourcesis fed back. The quantized value of the corresponding received powermeasurement value can be directly fed back, or the index correspondingto the measured value is fed back according to a preset lookup table.

1.h A threshold is set in advance, and an indication indicating whetherthe value measured on the measurement time-frequency resources is higherthan the threshold is fed back.

1.i Multiple thresholds are set in advance, and the feedback value isdetermined based on the comparison between the measured value and themultiple thresholds.

2. Feeding back the degree of impact of the measured cross-linkinterference on MCS level

Possible manners in this method include:

2.a The MCS level determined by taking the cross-link interference intoaccount is fed back.

The terminal device determines the MCS level by taking the cross-linkinterference into account according to the measurement result obtainedfrom the measurement and the measurement of the downlink referencesignal and feeds back the MCS level.

Specifically, when cross-link interference is not considered, theterminal device determines the downlink MCS level only based on themeasurement result of the downlink reference signal. However, it maytake into account that cross-link interference may cause interference tothe downlink, which affects the determination of the MCS level.Therefore, the terminal device calculates and determines a new MCS levelbased on the measurement result of the downlink reference signal (forexample, the measurement result of CSI-RS or DMRS or SSB) along with themeasurement result of cross-link interference, and feeds it back to thebase station.

2.b The MCS level adjustment step determined by taking the cross-linkinterference into account is fed back.

In the foregoing manner, the MCS level determined by taking thecross-link interference into account is fed back directly. The requirednumber of bits is the same as the number of feedback bits of the MCSlevel, and the required signaling overhead is large. In order to reducethe signaling overhead, the MCS level adjustment step can be fed back.The feedback may be performed by means of a look-up table, whichspecifies a relationship between an index (that is, a feedback bitcombination) and an MCS level adjustment step in a preset manner. Asimple lookup is shown in Table 1.

TABLE 1 Index (decimal representation MCS level of bit combination)adjustment step 0 unchanged or lowered 1 increase by 1 2 increase by 2 3increase by 3 or more

After measuring the cross-link interference, the terminal devicedetermines the MCS level adjustment step according to the measurementresult, selects an appropriate index from the lookup table, and feeds itback to the base station.

For different configuration methods of the measurement time-frequencyresources and reference signal sequence, the manner for feeding back theMCS level or the MCS level adjustment step may include at least one ofthe following methods:

The MCS level or MCS level adjustment step corresponding to eachreference sequence is fed back according to the configured referencesequence;

The MCS level or MCS level adjustment step corresponding to each combstructure is fed back according to the configured comb structure;

The MCS level or the MCS level adjustment step calculated for theconfigured downlink measurement time-frequency resources is fed back.

3. Feeding back an indication which indicates whether to continue toreceive downlink data on the current time-frequency resource

This method is equivalent to feedback an indication which indicateswhether the terminal device is capable of being scheduled to receivedownlink data on the current time-frequency resources, that is, whetherit can operate in a full duplex mode. For each configured referencesignal sequence, or comb structure, or time-frequency resources, only 1bit of information can be fed back, which is used to indicate whether aterminal device that can transmit an uplink reference signal can bescheduled on the same time-frequency resources. This data is hereinafterreferred to as instruction information.

For different configuration methods of the downlink measurementtime-frequency resources and sequence, the feedback method may includethe following:

3.a If downlink measurement time-frequency resources and referencesignal sequences are configured, corresponding indication information isfed back for each configured reference signal sequence.

3.b If downlink measurement time-frequency resources and comb structuresare configured, corresponding indication information is fed back foreach configured comb structure.

3.c If the downlink measurement time-frequency resources are configured,the corresponding indication information of the time-frequency resourcesis fed back.

After the terminal device performs feedback, it waits for furtherscheduling information of the base station to perform downlink datareception.

In the above embodiment, a method for reducing cross-link interferencein a cell generated between terminal devices having oppositetransmission directions that are served on the same time-frequencyresources in the same cell.

In the method, the base station configures reference signal resources(including reference signal time-frequency resources and/or referencesignal sequence resources) for the uplink terminal device (that is, theterminal device performing uplink transmission); meanwhile, the basestation configures measurement resources (including time-frequencyresources for measurement and/or sequence resources for measurement) forthe downlink terminal device (that is, the terminal device performingdownlink transmission), where all available reference signaltime-frequency resources configured for the uplink terminal device andall available measurement time-frequency resources configured for thedownlink terminal device overlap each other. The uplink reference signaltime-frequency resources configured for a single terminal device is asubset of all available reference signal time-frequency resources; thedownlink measurement time-frequency resources configured for a singleterminal device is a subset of all available measurement time-frequencyresources.

The base station allocates periodic measurement resources and/orsequence resources to the terminal device receiving the downlink data.After receiving the configuration, the downlink terminal deviceperiodically measures the cross-link interference on the measurementtime-frequency resources and feeds back the corresponding measurementresult. For a configuration manner of downlink measurementtime-frequency resources and/or sequence resources, and a measurementand feedback manner, reference may be made to the description of theforegoing method 300.

Since the periodic measurement and feedback cannot reflect the suddenchange of the channel, in the following embodiments, an aperiodiccross-link interference measurement and feedback method will beprovided.

Aperiodic Downlink Measurement and Feedback

The terminal device that receives the downlink data is subject to thecross-link interference. By using the foregoing periodic measurement andfeedback, it is convenient for the base station to reduce the impact ofcross-link interference on downlink reception through scheduling and thelike. However, when there are changes in the communication channel,especially sudden changes, periodic measurement and feedback oftencannot reflect such changes in time, resulting in a decrease in thereliability of the downlink received data. At this time, throughaperiodic downlink measurement and feedback, the impact of such suddenchannel changes on data transmission can be reduced.

Specifically, the aperiodic downlink measurement and feedback can betriggered by a downlink terminal device or a base station. If it istriggered by a downlink terminal device, the downlink terminal deviceacts as follows:

sending a downlink measurement request on the uplink channel;

receiving downlink measurement time-frequency resource configurationinformation and/or sequence resource configuration information from thebase station, where the measurement time-frequency resourceconfiguration information and/or sequence resource configurationinformation received from the base station is configured by the basestation in response to the downlink measurement request;

performing measurement on downlink measurement time-frequency resourcesconfigured by the base station; and

feeding back the measurement result to the base station.

When measuring the cross-link interference, an uplink terminal devicepaired with a downlink terminal device needs to transmit a referencesignal so that the downlink terminal device can perform the measurement.At this time, the uplink terminal device acts as follows:

receiving uplink reference signal time-frequency resource configurationinformation and/or reference signal sequence resource configurationinformation configured by the base station; and

transmitting the reference signal on the time-frequency resourcesconfigured by the base station.

It should be noted that the measurement time-frequency resourcesconfigured for the downlink terminal device and the reference signaltime-frequency resources configured for the uplink terminal deviceshould overlap with each other. When the uplink terminal devicetransmitting a reference signal, the downlink terminal device shouldstart the measurement.

The aforementioned aperiodic measurement and feedback method is shown inFIG. 7 .

FIG. 7 schematically illustrates an aperiodic measurement and feedbackmanner according to an embodiment of the present disclosure.

The downlink terminal device transmits the downlink measurement requestby:

transmitting the downlink measurement request in the uplink controlchannel or uplink shared channel. The measurement request may be 1-bitinstruction information, which is used to inform the base station thatthe current terminal device needs to perform downlink measurement.

The time-frequency resource configuration information and/or referencesignal configuration information may be received as follows.

For a downlink terminal device, the time-frequency resources and/orreference signal configuration information for downlink measurement isreceived in the downlink control information.

For the reference signal configuration information, the possible mannersinclude:

a. Obtaining all configuration information of the reference signalsequence in the downlink control channel, including cyclic shiftconfiguration information of the reference signal sequence, combstructure configuration information, and the like.

b. Obtaining part of the configuration information of the referencesignal sequence in the downlink control channel, including the combstructure configuration information.

c. Not obtaining any reference signal configuration information.

For the uplink terminal device, all configuration information of thereference signal sequence for measurement needs to be received in thedownlink control information.

For the feedback of the cross-link interference, it needs to bedetermined according to the specific sequence configuration mode, andall the methods listed in the foregoing embodiments can be used.

After the downlink terminal device completes the measurement andfeedback of the cross-link interference, it receives the schedulinginformation of the base station and performs the subsequent datatransmission process.

In another embodiment, the aforementioned aperiodic downlink measurementand feedback may also be triggered by a base station. In this case, thebase station directly transmits time-frequency resource configurationinformation for measurement, and instructs the corresponding uplinkterminal device to transmit a reference signal sequence on thecorresponding time-frequency resources. After receiving thetime-frequency resource configuration information, the uplink terminaldevice transmits a reference signal sequence on the correspondingtime-frequency resource; after receiving the time-frequency resourceconfiguration information, the downlink terminal device performsdownlink measurement on the corresponding time-frequency resources andfeeds back the corresponding measurement result.

Semi-Static Downlink Measurement and Feedback

For a downlink terminal device that operates in full duplex mode, it isstill necessary to measure the paired uplink terminal device andfeedback the corresponding measurement result. At this time, asemi-static configuration manner can be used to measure the cross-linkinterference caused by the paired uplink terminal device.

A possible implementation manner is that the downlink terminal deviceobtains configuration information of the semi-static measurementtime-frequency resources from the system information or the downlinkcontrol channel. The time-frequency resource configuration informationincludes time-frequency resource location of the measurement resources,periodicity information, and the like.

The downlink terminal device obtains an activation instruction of theforegoing semi-static measurement time-frequency resources from thedownlink control information. After receiving the activationinstruction, measurement of cross-link interference is started on thesemi-static measurement time-frequency resources configured by the basestation, and the corresponding measurement result is fed back.

The downlink terminal device detects the downlink control information,and stops the measurement and feedback if a deactivation instruction ofthe semi-static measurement time-frequency resources is detected.

In another embodiment, the downlink terminal device obtainsconfiguration information of the semi-static measurement time-frequencyresources from the system information or the downlink control channel.The configuration information may include a time-frequency resourcelocation of the measurement resources, a start time and an end time (ora valid time length) of the measurement resources, and a period withinthe valid time length.

After receiving the configuration information of the semi-staticmeasurement time-frequency resources, the terminal device performscross-link interference measurement within a valid time indicated in theconfiguration information, and feeds back corresponding measurementresult.

In this way, the terminal device can monitor the downlink controlinformation at the same time. If the downlink control informationcarries the deactivation indication of the semi-static measurementtime-frequency resources, the measurement and feedback on thesemi-static measurement time-frequency resources are stopped.

According to the method provided by the embodiment of the presentdisclosure, the impact of inaccurate cross-link interference measurementon downlink data transmission due to channel changes can be reduced,thereby improving the overall performance of the system.

Hereinafter, a method for determining the cross-link interferenceperformed at a base station according to an embodiment of the presentdisclosure will be described with reference to FIG. 8 .

FIG. 8 schematically illustrates a flowchart of a method 800 fordetermining the cross-link interference performed at a base stationaccording to an embodiment of the present disclosure. For simplicity,details that have been described in detail in the corresponding method300 for measuring the cross-link interference performed at a terminaldevice as described previously with reference to FIG. 3 are omittedhere. For details, reference may be made to the foregoing description ofthe method 300.

As shown in FIG. 8 , the method 800 may include steps S801 to S804.

In step S801, the base station may configure time-frequency resourcesfor the terminal device. Here, the time-frequency resources may includemeasurement time-frequency resources for measuring the cross-linkinterference.

Further, in step S802, the base station may transmit the time-frequencyresource configuration information to the terminal device.

Alternatively, or additionally, the base station may configure sequenceresources for the terminal device in step S801 and transmits thesequence resource configuration information to the terminal device instep S802. Here, the sequence resource configuration information mayinclude at least one of: a root sequence configuration of a usedreference signal sequence, a cyclic shift configuration, and a combstructure configuration.

As described above, in an embodiment, step S801 may include configuring,as the measurement time-frequency resources, reference signaltime-frequency resources for the terminal device.

In another embodiment, step S801 may include configuring a set ofreference signal time-frequency resources and a resource index setindication for the terminal device. The terminal device can use the setof reference signal resources and the resource index set indication todetermine reference signal time-frequency resources for uplink soundingand the measurement time-frequency resources for downlink measurement.

In an embodiment, step S801 may include at least one of:

configuring a period of the reference signal time-frequency resources asa period of the measurement time-frequency resources,

configuring a period of the measurement time-frequency resourcesseparately, or

configuring time configuration information for the measurementtime-frequency resources separately.

In step S803, the base station may receive from the terminal device ameasurement result of cross-link interference measured by the terminaldevice on measurement time-frequency resources for measuring thecross-link interference determined according to the time-frequencyresource configuration information.

In an embodiment, step S803 may include:

receiving an RSRP measurement measured by the terminal device accordingto a reference signal sequence or a set of reference signal sequencestransmitted on the measurement time-frequency resources when theterminal device receives the sequence resource configurationinformation;

receiving received signal strength measured directly by the terminaldevice on the measurement time-frequency resources when the terminaldevice fails to receive the sequence resource configuration information.

The measurement result may include at least one of: the measured RSRP orreceived signal strength measured by the terminal device, the degree ofimpact of the measured cross-link interference on the MCS level, or anindication which indicates whether the terminal device is capable ofbeing scheduled to receive downlink data on the current time-frequencyresources.

In step S804, the base station may schedule the terminal deviceaccording to the measurement result.

In an embodiment, the method 800 may further include: receiving adownlink measurement request from the terminal device, whereinconfiguring the terminal device with time-frequency resources and/orsequence resources is performed by the base station in response to thedownlink measurement request, that is, it is performed aperiodically.

In another embodiment, step S801 may be performed periodically orsemi-statically.

The following describes the scheduling method of the base station indetail corresponding to the three measurement and feedback methods(periodic measurement and feedback, aperiodic measurement and feedback,and semi-static measurement and feedback) provided by the terminaldevice described previously.

Periodic Measurement and Feedback

The periodic measurement and feedback are mainly used to periodicallymeasure the cross-link interference between the downlink terminal deviceand the uplink terminal device, so as to determine the pairing situationof the downlink terminal device and the uplink terminal device in thefull duplex mode.

In this way, the base station maintains a terminal device list for eachdownlink terminal device, and records the interference of the uplinkterminal device with which it may be paired on its downlinktransmission.

One possible way is to establish a look-up table for each downlinkterminal device. The look-up table includes, for the downlink terminaldevice, the terminal device or terminal device group that can be pairedwith the downlink terminal device for uplink transmission, and themeasurement result obtained by the downlink terminal device measuringthe cross-link interference caused by the corresponding downlinkterminal device or terminal device group during uplink transmission.

In this manner, the base station performs scheduling of the uplinkterminal device and the downlink terminal device according to themeasurement result of the cross-link interference in the lookup table.Specifically, the base station selects an uplink terminal device pairedwith the downlink terminal device based on a cross-link interferencemeasurement result from a lookup table established for each downlinkterminal device according to a preset rule and performs scheduling anddata transmission. The measurement result is obtained by a downlinkterminal device performing measurement feedback on the downlinkmeasurement time-frequency resources configured by the base station.

The preset criteria may include the following:

1. Selecting an uplink terminal device with the lowest cross-linkinterference measurement value, pairing it with the aforementioneddownlink terminal device, and providing services on the sametime-frequency resources.

For this criterion, a first threshold can be set in advance. If thelowest value of the interference measurement value is greater than thefirst threshold, it means that the downlink terminal device does nothave a suitable matched uplink terminal device according to the currentmeasurement result, so the downlink terminal device is scheduled toreceive downlink data on time-frequency resources in a half-duplex mode.

2. Setting a second threshold in advance, selecting an uplink terminaldevice whose cross-link interference measurement value is lower than thesecond threshold in the lookup table, pairing it with the downlinkterminal device, and providing services on the same time-frequencyresources. If there is no uplink terminal device in the lookup tablewhose cross-link interference measurement value is lower than the secondthreshold, it means that the downlink terminal device does not have asuitable matched uplink terminal device according to the currentmeasurement result, so the downlink terminal device is scheduled toreceive downlink data on time-frequency resources in a half-duplex mode.

The foregoing lookup table is established in the following manner: thebase station receives the downlink measurement result fed back by thedownlink terminal device, determines the corresponding uplink terminaldevice or terminal device group according to the configured downlinkmeasurement time-frequency resources and/or sequence resources, andupdates or adds the corresponding measurement result in the lookuptable.

In another embodiment, the base station maintains an uplink terminaldevice list for each downlink terminal device, and the list records anuplink terminal device(s) that can be paired with the downlink terminaldevice. The uplink terminal device list is established in the followingmanner: a third threshold is set in advance; the base station receivesmeasurement feedback on the cross-link interference from the downlinkterminal device; and the base station determines the uplink terminaldevice or terminal device group that generate the cross-linkinterference according to the configured downlink measurementtime-frequency resources and/or sequence resources; the base stationcompares the feedback measurement result with the third threshold, andadds the uplink terminal device or terminal device group to the uplinkterminal device list of the downlink terminal device if it is lower thanthe third threshold; if it is higher than the third threshold, does notadd the uplink terminal device or terminal device group to the uplinkterminal device list of the downlink terminal device or remove from theuplink terminal device list of the downlink terminal device.

The base station selects an uplink terminal device paired with thedownlink terminal device for scheduling according to the uplink terminaldevice list of the downlink terminal device. For example, an uplinkterminal device is randomly selected with equal probability to be pairedwith the downlink terminal device in the uplink terminal device list ofthe downlink terminal device; or, the uplink terminal device with thesmallest measurement result in the uplink terminal device list of thedownlink terminal device is selected to be paired with the downlinkterminal device; or, a recently added uplink terminal device is selectedfrom the uplink terminal device list of the downlink terminal device forpairing.

If there is no terminal device in the uplink terminal device list of thedownlink terminal device (that is, the table is empty), it means thatthe downlink terminal device does not have a suitable matched uplinkterminal device according to the current measurement result, so thedownlink terminal device is scheduled to receive downlink data ontime-frequency resources in a half-duplex mode.

The periodic feedback and measurement can be used for the establishmentand long-term maintenance of the uplink terminal device list or thelookup table. Considering that sudden channel changes cannot be trackedby the periodic feedback and measurement, aperiodic measurement andfeedback are needed to supplement it.

Aperiodic Measurement and Feedback

As mentioned above, aperiodic measurement and feedback are mainly usedto measure the change in cross-link interference when the interferencechannel between a paired downlink terminal device and uplink terminaldevice changes. The aperiodic measurement and feedback can be triggeredby the downlink terminal device or by the base station.

When it is triggered by a downlink terminal device, the base stationreceives an aperiodic measurement request transmitted by the downlinkterminal device. After receiving the aperiodic measurement request, thebase station allocates measurement time-frequency resources andsequences, transmits configuration information of the measurementtime-frequency resources and/or sequences to the downlink terminaldevice through the downlink control channel, and simultaneouslytransmits the corresponding configuration information of the measurementtime-frequency resources and/or sequences to the uplink terminal devicethrough the downlink control channel. The base station receives themeasurement result information transmitted by the downlink terminaldevice, determines whether the level of cross-link interference haschanged, and performs subsequent scheduling process.

The determining whether the level of cross-link interference has changedand performing subsequent scheduling process includes:

Setting the fourth threshold in advance. If the base station uses theforegoing manner of maintaining an uplink terminal device lookup table,the fourth threshold may be the same as the foregoing first or secondthreshold or may be different. If the feedback measurement resultreceived by the base station from the downlink terminal device is lowerthan the fourth threshold, the current downlink terminal device and theuplink terminal device can still be paired for scheduling, and themeasurement result of the corresponding uplink terminal device in thelookup table is updated. If the feedback measurement result received bythe base station from the downlink terminal device is higher than thefourth threshold, the uplink terminal device lookup table of thedownlink terminal device is updated, and the updated lookup table issearched for the uplink terminal device for new scheduling that meetsthe foregoing conditions and can be paired with the downlink terminaldevice. If there is no uplink terminal device in the lookup table thatmeets the foregoing conditions and can be paired with the downlinkterminal device, it means that the downlink terminal device does nothave a suitable matched uplink terminal device according to the currentmeasurement result, so the downlink terminal device is scheduled toreceive downlink data on time-frequency resources in a half-duplex mode.

If the base station uses the foregoing manner of maintaining an uplinkterminal device list, the fourth threshold may be the same as ordifferent from the foregoing third threshold. The feedback measurementresult received by the base station from the downlink terminal device iscompared with the fourth threshold. if the measurement result is lowerthan the fourth threshold, the current downlink terminal device and theuplink terminal device may still be paired for scheduling; if themeasurement result is higher than the fourth threshold, the uplinkterminal device is removed from the uplink terminal device list (thatis, the uplink terminal device list is updated), and a new uplinkterminal device is selected from the uplink terminal device list forpairing scheduling with the downlink terminal device. If the uplinkterminal device list is empty after updating the uplink terminal devicelist, it means that the downlink terminal device does not have asuitable matched uplink terminal device according to the currentmeasurement result, so the downlink terminal device is scheduled toreceive downlink data on time-frequency resources in a half-duplex mode.

For the aperiodic measurement and feedback triggered by the basestation, the trigger condition may be that the base station receivesfeedback information of the downlink data received by the downlinkterminal device paired with the uplink terminal device. If it is foundthat the current MCS level is used, the hybrid automatic retransmissionfeedback information is Negative Acknowledgment (NACK), and the numberof retransmissions exceeds a predetermined threshold, it is consideredthat there is a problem with the current pairing of the downlinkterminal device and the uplink terminal device, thereby initiatingaperiodic measurement and feedback, and transmitting downlinkmeasurement time-frequency resources on the downlink control channel.The subsequent process is the same as the aperiodic measurement andfeedback initiated by the terminal device and is not repeated here.

Semi-Static Measurement and Feedback

In addition to periodic and aperiodic measurement and feedback,semi-static feedback can be used to detect the strength of interferencebetween a paired downlink terminal device and uplink terminal device.

When using semi-static measurement and feedback, the base stationconfigures semi-static measurement time-frequency resources and/orreference signal sequence resources for the downlink terminal devicethrough the downlink control channel, and configures semi-staticreference signal time-frequency resources and sequence resources for thecorresponding uplink terminal device through the downlink controlchannel. The base station receives the measurement result feedbackobtained by the downlink terminal device by measuring on thecorresponding semi-static resources and compares the measurement resultwith a predetermined threshold. If it is lower than the threshold, thecurrent downlink terminal device and the uplink terminal device canstill be paired for scheduling; if the measurement result is higher thanthe threshold, a new uplink terminal device is selected to be pairedwith the downlink terminal device for scheduling according to theforegoing rules, a semi-static measurement resource deactivationindication is transmitted in the downlink control channel to stop thecorresponding semi-static measurement and feedback.

The action of the base station and the action of the terminal device inthe aforementioned different states can be described as follows.

After the terminal device has accessed, it continuously performsperiodic measurement and feedback to measure the cross-link interferencegenerated by different uplink terminal devices when the terminal devicereceives downlink data. At this time, the different measurement unitsallocated to the same downlink terminal device may be allocated todifferent uplink terminal devices for transmitting uplink referencesignals, as shown in FIG. 9 .

FIG. 9 schematically illustrates a diagram of measuring cross-linkinterference of different terminal devices according to an embodiment ofthe present disclosure.

In this process, the base station continuously updates the uplinkterminal device list of the terminal device, and searches for a terminaldevice that can be paired with downlink reception of the terminal devicefor uplink data transmission. If a corresponding terminal device isfound, the downlink reception of the terminal device and the uplink datatransmission of the searched terminal device can be scheduled on thesame time-frequency resources, so the base station operates in afull-duplex mode.

At this time, the semi-static test time-frequency resources and/orsequence resources may be allocated to the downlink terminal device, soas to monitor cross-link interference caused by the paired terminaldevice.

The base station and/or the downlink terminal device may also initiateaperiodic measurement and feedback when the triggering conditions aremet, to monitor the sudden changes in the interference link between thepaired terminal device and the downlink terminal device.

During the scheduling process, periodic measurement and feedback arestill performed to continuously update the uplink terminal device list.The base station can adjust the period in the downlink controlinformation or system information to increase the feedback period andreduce signaling overhead.

If during the scheduling process, it is found that the current pairingis no longer suitable through semi-static or aperiodic measurement andfeedback, a new uplink terminal device is selected from the terminaldevice list for pairing with the downlink data reception of the terminaldevice. If there is no terminal device in the uplink terminal devicelist that meets the foregoing rule, the downlink data reception of theterminal device is scheduled to half-duplex resources until a suitablepaired uplink terminal device is found.

A manner of inter-cell interference coordination according to anembodiment of the present disclosure will be described below.

In the scenario assumed by this embodiment, the system uses a flexibletime division duplex frame structure configuration. Due to factors suchas service types or data requirements of terminal devices, neighboringcells are configured with different transmission directions on the sametime-frequency resources, which results in cross-link interferencebetween terminal devices at the cell edge. A simple explanation is asfollows.

Cell 1 is scheduled for downlink transmission at time N, and neighboringcell 2 is scheduled for uplink transmission on the same time-frequencyresources. At this time, cross-link interference will occur betweenterminal devices at the edge of the two cells. Specifically, the uplinkdata transmission of the terminal device B in the cell 2 may interferewith the downlink data reception of the terminal device A in the cell 1.

For the interference, the impact of the interference on the downlinkdata reception can be reduced through inter-cell cooperation. Onepossible way is to share time-frequency resources of the uplink soundingreference signal between cells, and configure the measurementtime-frequency resources for the downlink terminal device in thedownlink cell to measure the inter cell interference caused by theadjacent uplink cell to the cell edge terminal device. The measurementtime-frequency resources configured by the downlink cell for thedownlink terminal device overlaps with the uplink sounding referencesignal resources of at least one adjacent uplink cell.

The measurement time-frequency resources configured by the downlink cellfor the downlink terminal device may be dedicated to the terminaldevice. For example, for the cell center terminal device, the foregoingmeasurement time-frequency resources are not configured, and for thecell edge terminal device, it is determined whether to configure theforegoing measurement time-frequency resources for the cell edgeterminal device according to the transmission direction of theneighboring cell.

FIG. 10 shows a simple example.

FIG. 10 schematically illustrates a configuration manner of downlinkmeasurement time-frequency resources according to an embodiment of thepresent disclosure.

Referring to FIG. 10 , all three time slots of the base station 1 aredownlink time slots and serve three terminal devices A, B, and C at thesame time. The terminal device B is located at the cell center of thecell 1, so no measurement time-frequency resource is configured for theterminal device. Terminal device A is located at the cell edge of theserving cells of base station 1 and base station 2, and it is determinedwhether to configure measurement time-frequency resources according tothe transmission direction of base station 2. The three slottransmission directions of base station 2 are: downlink, uplink, anddownlink. It can be seen that the transmission directions of the basestation 1 and the base station 2 in time slot 2 are different, so theterminal device A is configured with measurement the time-frequencyresources in time slot 2. The terminal device C is located at the celledge of the serving cells of the base station 1 and the base station 3,and it is determined whether to configure the measurement time-frequencyresources according to the transmission direction of the base station 3.The three timeslot transmission directions of the base station 3 are:uplink, downlink, and uplink. The transmission directions are differentfrom the transmission direction of the base station 1 in time slots 1and 3. Therefore, the base station 1 configures measurementtime-frequency resources for the terminal device C in time slots 1 and3.

In another implementation manner, the measurement time-frequencyresources of the downlink base station are configured according towhether the terminal device is located at a cell edge. If the terminaldevice is located at the cell edge, the terminal device is configuredwith measurement time-frequency resources in the downlink time slot orsymbol; if the terminal device is located at the cell center, nomeasurement time-frequency resource is configured.

The foregoing measurement time-frequency resources may be sent andnotified in a downlink control channel and may also be sent and notifiedin the system information. After receiving the configuration informationof the measurement time-frequency resources, the terminal deviceperforms measurement on the corresponding time-frequency resources andfeeds back the corresponding measurement result.

The feedback measurement result may be a directly quantified RSRP, or acorresponding index value may be determined using a corresponding lookuptable according to the measurement result and fed back.

After receiving the feedback from the downlink terminal device, the basestation may transmit the feedback measurement result to the base stationthat generates cross-link interference through the backhaul link.

In another embodiment, the base station compares the feedback of thedownlink terminal device with a preset threshold. If the feedback resultis lower than the threshold, it means that the inter-cell cross-linkinterference caused by the neighboring base station is low andinsufficient to affect the reception of downlink data, and the feedbackresult is not transmitted to the base station causing the interference;if the feedback result is higher than the threshold, it means that theinter-cell cross-link interference received by the downlink terminaldevice is serious, and the base station transmits the correspondingfeedback result to the corresponding base station through the backhaullink.

In addition, rather than directly transmitting the feedback result tothe corresponding interfering base station, the current base station maytransmit instruction information indicating whether there is inter-cellcross-link interference, to notify the interference situation of theneighboring interfering base station.

When the neighboring base station receives the indication information ormeasurement result transmitted by the current base station through thebackhaul link, it can choose a scheduling mode to reduce inter-cellcross-link interference on the downlink terminal device in theneighboring cell.

In another embodiment, new reference signal time-frequency resources andreference signal sequences may be defined, which are specifically usedfor measurement of inter-cell cross-link interference. In this way, thecurrent base station transmits configuration information to the downlinkterminal device and configures time-frequency resources for measurement.In a cell that is served by the interfering base station, the basestation configures reference signal time-frequency resources andcorresponding reference signal sequences. It should be noted that thetime-frequency resources for measurement and the reference signaltime-frequency resources overlap each other.

In addition to the configuration information, the foregoing process canbe used for the interaction between the base station and the terminaldevice.

The structure of a terminal device according to an embodiment of thepresent disclosure will be described below with reference to FIG. 11 .

FIG. 11 schematically illustrates a structural block diagram of aterminal device 1100 according to an embodiment of the presentdisclosure. The terminal device 1100 may be used to perform the method300 as described previously with reference to FIG. 3 .

As shown in FIG. 11 , the terminal device 1100 includes: a processingunit or a processor 1101, which processor 1101 may be a single unit or acombination of multiple units for performing different steps of amethod; a memory 1102, which stores a computer executable instructionsthat, when executed by the processor 1101, cause the terminal device1100 to perform the method 300. For simplicity, only the schematicstructure of a terminal device according to an embodiment of the presentdisclosure is described herein, and details that have been described indetail in the method 300 described previously with reference to FIG. 3are omitted.

The structure of a base station according to an embodiment of thepresent disclosure will be described below with reference to FIG. 12 .FIG. 12 schematically illustrates a structural block diagram of a basestation 1200 according to an embodiment of the present disclosure. Thebase station 1200 may be configured to perform the method 800 aspreviously described with reference to FIG. 8 .

As shown in FIG. 12 , the base station 1200 includes: a processing unitor a processor 1201, which processor 1201 may be a single unit or acombination of multiple units for performing different steps of themethod; a memory 1202, which stores computer-executable instructionsthat, when executed by the processor 1101, cause the base station 1200to perform the method 800. For simplicity, only the schematic structureof a base station according to an embodiment of the present disclosureis described herein, and details that have been described in detail inthe method 800 described previously with reference to FIG. 8 areomitted.

In addition, in order to overcome the problem of a long access delayexisting in the existing wireless communication technology, according toan embodiment of the present disclosure, there is provided a physicalrandom access channel, and the physical random access channel mayinclude a random access preamble and a cyclic prefix of the randomaccess preamble, wherein a sub-carrier space corresponding to the randomaccess preamble is lower than 1.25 KHz.

As for a general physical random access channel, a sub-carrier space isequal to 1.25 KHz. As for the physical random access channel accordingto the embodiment of the present disclosure, the sub-carrier space islower than 1.25 KHz, that is, the sub-carrier space is reduced. Since areciprocal of the sub-carrier space is a length of the random accesspreamble, the length of the random access preamble is increased.Increasing the length of the random access preamble makes a probability,in which the random access preamble is identified, be increased so as toincrease a success rate of performing a random access by using therandom access preamble.

The physical random access channel according to the embodiment of thepresent disclosure is applicable to a full-duplex system, to support theadjacent cells to transmit a longer random access preamble on anidentical physical random access channel (PRACH) resource, so as toimprove a resource usage rate and a random access success rate.

As an example, the sub-carrier space can be equal to 1 KHz. In thiscase, as illustrated in the description with reference to FIG. 13 below,the physical random access channel further includes a pre guard period,and the pre guard period and the cyclic prefix of the random accesspreamble are located in a transmission time interval prior to thetransmission time interval where the random access preamble is located.

As an example, the sub-carrier space may be higher than 1 KHz and lowerthan 1.25 KHz. In this case, as illustrated in the description withreference to FIG. 14 below, the physical random access channel furtherincludes the pre guard period and the post guard period, and a sum oflengths of the following items is 1 ms or 30720Ts: the pre guard period,the cyclic prefix of the random access preamble, the random accesspreamble, and the post guard period. Here, 1Ts indicates 1/(30.72*10⁶)seconds.

According to another embodiment of the present disclosure, there isprovided a random access preamble allocation method, which includes:configuring a random access preamble, wherein a sub-carrier spacecorresponding to the configured random access preamble is lower than1.25 KHz. The characteristic of the random access preamble can beimplemented by referring to the above embodiment. The random accesspreamble allocation method can be performed through a network layer forparameter allocation.

More particularly, the embodiment shown in FIG. 14 may include one ofthe following cases: a length of the pre guard period is equal to alength of the cyclic prefix of the random access preamble, and a lengthof a post guard period is zero; the length of the pre guard period isequal to the length of the cyclic prefix of the random access preamble,and a difference between a sum of lengths, which include a length of thepost guard period and a length of the cyclic prefix of a first OFDMsymbol of the transmission time interval subsequent to the transmissiontime interval where the random access preamble is located, and thelength of the cyclic prefix of the random access preamble is smallerthan or equal to 2Ts (for example, 0Ts); and the length of the postguard period is equal to the length of the cyclic prefix of the randomaccess preamble. When the length of the post guard period is zero, thecyclic prefix of the first OFDM symbol of the transmission time intervalsubsequent to the transmission time interval, where the random accesspreamble is located, functions as the post guard period of the randomaccess preamble.

A specific structure of the physical random access channel according tothe embodiment of the present disclosure will be described in detailsbelow.

FIG. 13 shows a diagram of at least one portion of a frame including arandom access preamble according to an embodiment of the presentdisclosure.

In FIG. 13 , a horizontal coordinate indicates time (a time domain), anda vertical coordinate indicates a frequency (a frequency domain). FIG.13 includes the physical random access channel according to theembodiment of the present disclosure, and the physical random accesschannel included in FIG. 13 at least is applicable to a random access ofa small cell, for example, applicable to a cell of which a radius issmaller than the small cell.

As shown in FIG. 13 , the transmission time interval may be 1millisecond (ms), CP is a cyclic prefix of the random access preamble, aguard band may be configured on the frequency domain, and the guardperiod can be configured on the time domain. Structure parameters of thephysical random access channel according to the embodiment of thepresent disclosure are shown in the following Table 2.

TABLE 2 Random access Resource bandwidth Sub-carrier space preamblelength of PRACH 1 KHz 1 ms 1.08 MHz Guard band on frequency ZC sequenceLength and location of domain length cyclic prefix Bandwidth of each oftwo 1049 Occupying 0.5 OFDM guard bands is 23 KHz symbols, namely, thelast 0.5 OFDM symbols within a previous 1 ms

With reference to Table 2, structure parameters of PRACH of theembodiment of the present disclosure are explained below:

(1) Resource Bandwidth of PRACH

In order to ensure there still exist sufficient resources allocated to auser to perform the random access in the case of the smallest systembandwidth, similar to a long term evolution (LTE) or new radio (NR)system, a bandwidth carrying the PRACH resource of the random accesspreamble (that is, a resource bandwidth of the PRACH) is still designedto be 1.08 MHz.

(2) Sub-Carrier Space and Length of Random Access Preamble

A cyclic prefix on an orthogonal frequency division multiplexing (OFDM)symbol of a conventional data (for example, the data in FIG. 13 ) isusually 5 μs (microsecond). The length of the post guard period isenabled to be zero, and the cyclic prefix of the first OFDM symbol ofthe transmission time interval subsequent to the transmission timeinterval for transmitting the random access preamble is enabled tofunction as the post guard period of the random access preamble.

As an example, it is also possible to make a latter half of the lastOFDM symbol within the previous transmission time interval prior to thetransmission time interval for transmitting the random access preamblebe used for transmitting the cyclic prefix of the random access preambleand make a first half of the last OFDM symbol be used as the pre guardperiod. Adopting a frame structure shown in FIG. 13 to perform a randomaccess can make a covering radius at least reach 700 m, even reach 750m, so that a coverage requirement of the small cell with a radius of 500m or the cell of which the radius is smaller than that of the small cellcan be met.

Accordingly, the random access preamble according to the embodiment ofthe present disclosure may not retain the guard period of the randomaccess preamble in an LTE system or an NR system within the transmissiontime interval for transmitting the random access preamble, so that alonger time domain range may be reserved for the random access preamble.Since the longer the random access preamble is, the easier the randomaccess preamble is to be detected, the random access preamble accordingto the embodiment of the present disclosure may be detected more easily.

In addition, there is an orthogonality between the sub-carrier space ofthe conventional data and the sub-carrier space of the random accesspreamble, that is to say, the sub-carrier space Δf_(data) of theconventional data and the sub-carrier space Δf_(preamble) of the randomaccess preamble satisfy: Δf_(data)=K×Δf_(preamble), wherein K is apositive integer, the sub-carrier space Δf_(preamble) is a reciprocal ofa random access preamble length T_(SEQ), for example, when the randomaccess preamble length T_(SEQ) is 1 ms, the sub-carrier spaceΔf_(preamble) is 1 kHz.

(3) Length and Location of the Cyclic Prefix

Configuring the cyclic prefix is an effective means against a multi-patheffect, and whatever a radius of the cell is, the cyclic prefix shouldbe retained, and a length of the cyclic prefix is at least the greatesttime delay spread of a spatial propagation channel.

In order to maximize the detection ability for the random accesspreamble, the length of the random access preamble may be designed to be1 ms. As shown in FIG. 13 , the length of the cyclic prefix of therandom access preamble may be designed to be 0.5 conventional OFDMsymbol, and disposed at the latter half of the last symbol in thetransmission time interval prior to the transmission time interval fortransmitting the random access preamble, and the first half of the lastsymbol serves as the guard period.

(4) Guard Band and ZC (which is Zadoff-Chu, and is Called ZC for Short)Sequence Length on the Frequency Domain.

In order to distinguish the random access preamble from the conventionaldata or other data, and to protect the random access preamble, the guardband designed in the LTE system or the NR system may be used, the ZCsequence length N_(ZC) may be designed to be greater than 839, forexample, N_(ZC)=1049. Compared with the ZC sequence with a length of 839in the LTE system or the NR system, the ZC sequence length in thepresent embodiment may at least increase 25%, and accordingly, adetection performance may at least be improved by 10% in theory.

As described above, the cyclic prefix of the random access preamble maybe located within the last OFDM symbol of the transmission time intervalprior to the transmission time interval where the random access preambleis located; a portion of the last OFDM symbol of which the time isprevious to that of another portion serves as the pre guard period ofthe random access preamble; and the other portion of the last OFDMsymbol serves as the cyclic prefix.

It should be understood that the above description is only used tofacilitate explanation of the present disclosure, and is not used tolimit the protection scope of the present disclosure, and in the casewhere the sub-carrier space corresponding to the random access preambleis enabled to be lower than 1.25 KHz, various manners may be adopted toconfigure the physical random access channel.

FIG. 14 shows a diagram of a physical random access channel according toan embodiment of the present disclosure.

As shown in FIG. 14 , the physical random access channel according tothe embodiment of the present disclosure may include a pre guard periodG1, a post guard period G2, a cyclic prefix CP and a random accesspreamble, wherein a sub-carrier space corresponding to the random accesspreamble is higher than 1 KHz and lower than 1.25 KHz.

Table 3 shows six configuration manners of the physical random accesschannel in the case where the sub-carrier space corresponding to therandom access preamble is higher than 1 KHz and lower than 1.25 KHz.

TABLE 3 Random access Sub- Length Con- preamble carrier CP of prefiguration length space length guard period 0 26624 Ts 1.154 kHz 2048 Ts2048 Ts 1 26624 Ts 1.154 kHz 1418 Ts 1418 Ts 2 26624 Ts 1.154 kHz 2048Ts 0 3 28672 Ts 1.071 kHz 1024 Ts 1024 Ts 4 28672 Ts 1.071 kHz  736 Ts 736 Ts 5 28672 Ts 1.071 kHz 1024 Ts 0

In the six configurations including Configuration 0 to Configuration 5,a sum of a length of the random access preamble, a length of the cyclicprefix of the random access preamble, a length of the pre guard period,and a length of the post guard period is a specific value (for example,30720Ts). When the length of the random access preamble is determined,the length of each of the cyclic prefix, the pre guard period and thepost guard period can be flexibly allocated according to a practicalrequirement. Lengths of at least two of the cyclic prefix, the pre guardperiod, and the post guard period can be broadcast in the cell through abroadcasting manner.

With reference to Table 3, in Configuration 0 and Configuration 3, adifference between the length of the cyclic prefix of the random accessleading sequence and the length of the pre guard period is smaller thanor equal to 2Ts (for example, 0Ts), and the length of the post guardperiod is zero; and in this case, the cyclic prefix of the first OFDMsymbol of the transmission time interval subsequent to the transmissiontime interval where the random access preamble is located may perform afunction of the post guard period of the random access preamble.Accordingly, the configured PRACH may not include the post guard period,but includes the pre guard period and the cyclic prefix of the randomaccess preamble, and a time domain length of the pre guard period isequal to a time domain length of the cyclic prefix of the random accesspreamble. Configuration 0 and Configuration 3 are applicable to a scenewhere a radius of the cell is very small (for example, smaller than 500m).

In Configuration 1 and Configuration 4, the PRACH may include the preguard period, the cyclic prefix of the random access preamble, and thepost guard period, a difference between the length of the pre guardperiod and the length of the cyclic prefix of the random access preambleis smaller than or equal to 2Ts (for example, 0Ts), and a differencebetween a sum of lengths, which include the length of the post guardperiod and the length of the cyclic prefix of the first OFDM symbol ofthe subsequent transmission time interval, and the length of the cyclicprefix of the random access preamble is smaller than or equal to 2Ts(for example, 0Ts). Configuration 1 and Configuration 4 are applicableto a scene where a radius of the cell is a little larger (for example,larger than a radius of the cell where Configuration 0 and Configuration3 are applicable).

In Configuration 2 and Configuration 5, the PRACH may not include thepre guard period (that is, the length of the pre guard period is zero),the difference between the length of the post guard period and thelength of the cyclic prefix of the random access preamble is smallerthan or equal to 2Ts (for example, 0Ts), and the configurations areapplicable to a scene where a radius of the cell is larger (larger thanthe radius of the cell where Configuration 1 and Configuration 4 areapplicable).

In the embodiment of the present disclosure, there are provided variousPRACHs. When performing the random access, the method and procedure inthe LTE system or the NR system may be used for performing the access.

In addition, when the PRACH according to the embodiment of the presentdisclosure is used, it is further necessary to consider the problem ofinterference.

Particularly, for example, in the embodiment shown in FIG. 13 , thecyclic prefix of the random access preamble is located within thetransmission time interval prior to the transmission time interval fortransmitting the random access preamble, and when the base stationschedules another terminal to perform uplink and downlink datatransmissions within a previous transmission time interval (thetransmission time interval prior to the transmission time interval fortransmitting the random access preamble), there may be resource overlapbetween the data of the last OFDM symbol of the previous transmissiontime interval and the cyclic prefix of the random access preamble. Whenthere is the resource overlap, the uplink and downlink datatransmissions will be interfered by the cyclic prefix of the randomaccess preamble. An interference case is described with reference toFIGS. 15-17 below when there is the resource overlap.

In FIG. 15 , a terminal 1 is a terminal to be accessed, a terminal 2 isa terminal of receiving a downlink data from the base station, and aterminal 3 is a terminal of transmitting an uplink data to the basestation.

With reference to FIGS. 15 and 16 , when the scheduling of the basestation is received, the resource scheduled to terminals (for example,the terminal 2 and the terminal 3) that have been accessed is in thetransmission time interval prior to the PRACH resource (the resource oftransmitting the random access preamble) for the random access, andoverlaps with the PRACH resource in a frequency domain, it is necessaryto perform a corresponding processing.

As shown in FIG. 16 , in performing the uplink data transmission, anuplink data 1 and an uplink data 2 are transmitted through a sub-framen, and the uplink data 2 occupies one OFDM symbol. In a transmissionprocess of the random access preamble, a portion of the CP of the randomaccess preamble is also transmitted through the sub-frame n, and even aportion of the pre guard period G and the CP of the random accesspreamble is transmitted through the sub-frame n, wherein the pre guardperiod G and the CP occupy one OFDM symbol. In this case, there is anoverlap with respect to time between a rear portion of the uplink data 2and the cyclic prefix of the random access preamble, so that the uplinkdata is interfered by the CP.

Particularly, when the base station starts to transmit the last OFDMsymbol of the sub-frame n at a time t, due to a two-way time delay, andfrom a view of the terminal, the base station starts to transmit thelast OFDM symbol of the sub-frame n at time t+ δt, wherein δt is aone-way time delay. At this time, the terminal will do not know how muchtime should be advanced to perform a signal transmission due to notperforming uplink synchronization. In this case, time t+ δt is selectedto start to transmit the random access preamble, and the transmittedrandom access preamble can arrive at the base station through theone-way time delay with a length of δt, so from the view of the basestation, the terminal starts to transmit the random access preamble attime t+2 δt, and in this case, as shown in FIG. 16 , the two-way timedelay is 2 δt. When the length of the two-way time delay cannot make thetransmission of the uplink data 2 be prevented from being interfered, itis necessary to perform a corresponding processing, for example, theprocessing shown in FIG. 18 .

As shown in FIG. 17 , in a procedure of performing the data transmissionor random access preamble transmission through the sub-frame n, theremay be the interference. For example, the base station can perform thedownlink data transmission, and in the process of the downlink datatransmission, the last OFDM symbol, the last but one OFDM symbol, andother symbols prior to the last but one OFDM symbol may be used. In theprocess that the accessed terminal receives the downlink data, the lastOFDM symbol, the last but one OFDM symbol, and other symbols prior tothe last but one OFDM symbol may be used. The accessed terminal not onlyreceives the downlink data from the base station, but also can passivelyreceive the random access preamble from another terminal, so that thesame accessed terminal has the process of receiving the downlink dataand the process of receiving the random access preamble. In the processthat the accessed terminal receives the random access preamble,according to magnitudes of a relative time delay and the one-way timedelay, the transmission of the random access preamble may performinterference on the accessed terminal which uses the last OFDM symbol totransmit the downlink data or using the last OFDM symbol and the lastbut one OFDM symbol to transmit the downlink data.

With reference to FIGS. 15 and 17 , the base station transmits thedownlink data on the last OFDM symbol of the sub-frame n at the time t,and the last OFDM symbol arrives at the terminal 2 through the time δt₁,that is, the terminal 2 starts to receive the downlink data from thetime t+ δt₁. The terminal 1 transmits the random access preamble at thetime t+ δt, and the random access preamble may arrive at the terminal 2through time δt₂, and thus, the terminal 2 starts to passively receivethe random access preamble of the terminal 1 at the time t+ δt₂.

The relative time delay is δt₂−δt₁, and when δt₂<δt₁, that is, adistance between the terminal 1 and the terminal 2 is closer than adistance between the base station and the terminal 2, the cyclic prefixof the random access preamble arrives at the terminal 2 earlier than thearrival of the downlink data carried by the last OFDM symbol, and inthis case, the transmission of the downlink data of the last but oneOFDM symbol may be interfered.

That is to say, a distance between the terminal to be accessed and theaccessed terminal is unknown, and thus as for the accessed terminal thatreceives the downlink data within the transmission time interval priorto the period of transmitting the random access preamble, although thebase station may configure that the accessed terminal does not receivedata on the last symbol, the downlink data of the last but one OFDMsymbol of the accessed terminal may also be interfered by the cyclicprefix of the passively received random access preamble. For example,when a distance between the terminal 2 of receiving the downlink dataand the base station is larger than a distance between the terminal andthe terminal 1 to be accessed in FIG. 15 , and the terminal 2 is locatedwithin the coverage of the terminal 1, not only the downlink data of thelast OFDM symbol with respect to the terminal 2 will be interfered bythe cyclic prefix of the random access preamble transmitted by theterminal 1, but also the downlink data of the last but one OFDM symbolwill be interfered by the cyclic prefix of the random access preamble,namely, the case shown in FIG. 17 .

In the embodiment of the present disclosure, when there is provided apre guard period before the cyclic prefix, the interference of thecyclic prefix of the random access preamble on the downlink data of thelast but one OFDM symbol may be prevented.

In order to solve the problem of the interference caused by the resourceoverlap, for example, the interference of the cyclic prefix of therandom access preamble on the downlink data of the last OFDM symbol, theaccessed terminal may also indicate whether to transmit or receive dataon the resource overlapped with the cyclic prefix of the random accesspreamble according to overlap resource transceiving data indicationinformation provided by the base station. When the base stationindicates that it is impossible to transmit or receive the data on theoverlapped resource, the terminal avoids the overlapped resource whentransmitting or receiving the data; and on the contrary, when the basestation indicates that data may be transmitted or received on theoverlapped resource, the terminal does not need to avoid the overlappedresource when transmitting or receiving the data. Here, the overlappedresource may indicate the overlapped resource both in the time domainand the frequency domain.

With reference to the flow diagram of a data transmission methodaccording to an embodiment of the present disclosure shown in FIG. 18 ,the terminal can perform the followings: at step S1810, receivingscheduling information from a base station; at step S1820, determiningwhether an allocated resource indicated by the scheduling informationfrom the base station includes a resource which is at least overlappedwith a cyclic prefix of a random access preamble or the random accesspreamble (for example, the resource overlapped with the cyclic prefix,the resource overlapped with the cyclic prefix and the random accesspreamble and the like); at step S1830, obtaining indication informationindicating whether transmission is allowed on the overlapped resource;and at step S1840, when a result of the determining indicates that thereis the overlapped resource and the indication information indicates thattransmission is allowed on the overlapped resource, transmitting thedata on the overlapped resource; and when the result indicates thatthere is the overlapped resource and the indication informationindicates that a user equipment shall avoid the overlapped resource whentransmitting the signal, avoiding the overlapped resource whentransmitting the data, wherein a sub-carrier space corresponding to therandom access preamble is equal to or smaller than 1 KHz, and at leastthe cyclic prefix of the random access preamble or the random accesspreamble is located in a transmission time interval prior to thetransmission time interval where the random access preamble is located.In addition, the resource which is scheduled to the terminal by the basestation and which is received by the terminal may be not in thetransmission time interval (the previous transmission time interval)prior to the random access preamble, or even the resource is in theprevious transmission time interval, the frequency domain resource mayalso be different from the frequency domain resource occupied by thecyclic prefix of the random access preamble, and there is no overlappedresource in above two cases. When there is no overlapped resource, theindication information is invalid indication information, and at thistime, data transmission may not be performed according to the indicationinformation.

The indication information may be transmitted or notified throughvarious manners, and for example, the indication information may betransmitted by using one bit in the downlink control informationcorresponding to a current scheduling, and can be notified to theterminal in the cell through a system information broadcasting manner,and can also be notified to the terminal when the terminal performs aradio resource control (RRC) connection.

According to the embodiment of the present disclosure, when a radius ofthe cell is relatively small (for example, the radius is smaller than orequal to 500 m (the radius of the small cell)), a solution that theadjacent cells share a logical root sequence number can be adopted, toat least partially eliminate the interference between the adjacent cellscaused by the random access preamble.

FIG. 19 illustrates a flow diagram of a random access preambleallocation method according to an embodiment of the present disclosure,to reduce an inter-cell interference, and the method can be performedthrough a network layer for parameter allocation.

As shown in FIG. 19 , the random access preamble allocation methodaccording to the embodiment of the present disclosure includes:

S1910, determining whether an interference strength between adjacentcells is greater than a strength threshold;

S1920, when the interference strength is greater than the strengththreshold, allocating, for each of the adjacent cells, an identical ZCsequence length, an identical cyclic shift interval, an identicallogical root sequence number, and different and continuous random accesspreamble set index numbers (that is, the random access preamble setindex numbers of the adjacent cells are different and continuous) foreach of the adjacent cells, wherein the ZC sequence length, the cyclicshift interval, the logical root sequence number, and the random accesspreamble set index number are configured to determine an availablerandom access preamble set of the each of the adjacent cells, and therandom access preamble generated from the identical logical rootsequence number exists in the random access preamble set correspondingto at least two continuous random access preamble set index numbers.Here, in the respective random access leading sequences generated fromthe identical logical root sequence number, any two random accesspreambles are orthogonal.

In addition, when the interference strength is lower than the strengththreshold, allocation is performed for any two cells according to one ofthe following manners: the logical root sequence numbers are mutuallydifferent and the random access preamble set index numbers are the same,the logical root sequence numbers are the same and the random accesspreamble set index numbers are mutually different, and the logical rootsequence numbers are mutually different and the random access preambleset index numbers are mutually different. As for the ZC sequence lengthsand the cyclic shift intervals, when the logical root sequence numbersare the same (that is, the random access preamble set index numbers aremutually different), the ZC sequence lengths are the same and the cyclicshift intervals are also the same; and when the logical root sequencenumbers are mutually different (that is, the random access preamble setindex numbers may be the same, and may also be mutually different), theZC sequence lengths of the two cells may be the same and the cyclicshift intervals may also be the same.

As an example, the cyclic shift index sequence may be generatedaccording to the following steps, wherein the cyclic shift indexsequence does not need to be practically generated, that is, the cyclicshift index sequence is only a virtual sequence:

according to the ZC sequence length and the cyclic shift interval,calculating a number of the random access preambles that can begenerated from one logical root sequence number, wherein the calculatednumber of the random access preambles is larger than a number of theavailable random access preambles of the cell; according to the logicalroot sequence number, generating cyclic shift indexes of which thenumber is the calculated number of the random access preambles; enablingthe logical root sequence number to be increased by 1, and according tothe logical root sequence number increased by 1, generating cyclic shiftindexes of which the number is the calculated number of the randomaccess preambles, wherein the present step (the step of enabling thelogical root sequence number to be increased by 1, and according to thelogical root sequence number increased by 1, generating the cyclic shiftindexes) is at least performed once; and arranging the generated cyclicshift indexes according to a predetermined order, to generate a cyclicshift index sequence (for example, the cyclic shift indexes generated byperforming the above step one of several times are arranged according anorder from small to large, and the cyclic shift index generated byperforming the above step in a former time is arranged before the cyclicshift index generated by performing the above step in a later time).

As an example, the allocating the random access preamble set indexnumbers includes: dividing the cyclic shift index sequences into aplurality of sets according to the number of the available random accesspreambles, each set corresponding to an unique random access preambleset index number; and allocating different random access preamble setindex numbers for each of the at least two adjacent cells.

As for the small cell with a radius of 500 m or the similar cell, thecyclic shift interval NCS of the random access preamble only needs to belarger than and equal to 9. In this case, the number of the randomaccess preambles that can be generated by one physical root sequencenumber may be 116. In the present embodiment, the number of theavailable random access preambles of each cell may be configured to be64.

Different from the LTE system and the NR system, the adjacent cells mayshare the identical cyclic shift interval NCS and the identical logicalroot sequence number (since the logical root sequence number correspondsto the physical root sequence number, the adjacent cells also share theidentical physical root sequence number), one unique random accesspreamble set index number may be allocated for each cell.

Particularly, the cyclic shift interval of the random access preamblesmay be configured to be NCS=9, and in conjunction with FIG. 20 , therandom access preamble allocation method according to the embodiment ofthe present disclosure is described.

With reference to FIG. 20 , the adjacent at least two cells share thecyclic shift interval NCS=9, and also share the identical logical rootsequence number. The number N of the random access preambles that can begenerated by one logical root sequence number can be calculated through[N_(ZC)/N_(CS)], wherein NZC indicates the ZC sequence length, └⋅┘indicates a round-down operation. For example, the number (N=116) of therandom access preambles that can be generated by one logical rootsequence number is obtained through calculation at the given ZC sequencelength.

In the case where the ZC sequence length, the logical root sequencenumber, and the cyclic shift interval are determined, a cyclic shiftindex vector {right arrow over (V)}_(L)=[v_(L) ⁰ . . . v_(L) ^(N−1)] canbe defined, the vector is explained only for convenient description, andin fact, the vector may not be generated, wherein v_(L) ⁰ indicates thecyclic shift index with respect to a value of the logical root sequencenumber L being 0, and the corresponding cyclic shift amount is v_(L)⁰·N_(CS); and v_(L) ¹ indicates the cyclic shift index with respect to avalue of the logical root sequence number L being 1, and thecorresponding cyclic shift amount is v_(L) ¹·N_(CS) and so forth. Whenthe random access preamble transmitted by the terminal is generatedaccording to the logical root sequence number L and the cyclic shiftamount is v_(L) ^(n)·N_(CS), the terminal selects the cyclic shift indexv_(L) ^(n), 0≤n<N.

The logical root sequence number shared by the cells can be indicated asLshared, and respective elements (that is, v_(L) _(shared) ⁰ to v_(L)_(shared) ^(N−1)) in a cyclic shift index vector generated according tothe logical root sequence number Lshared can be arranged from small tolarge according to the value of the logical root sequence number.Subsequently, the logical root sequence number is increased by 1, togenerate corresponding cyclic shift indexes and arrange the same (forexample, in the arrangement manner described in the embodiment of thepresent disclosure), such an operation is at least performed one time.Subsequently, the cyclic shift index sequence shown in FIG. 20 isformed.

Since the number of the available random access preambles of each cellis configured to be 64, the previous 64 cyclic shift index sequences maybe defined as a set 0, to be allocated to the cell of which the randomaccess preamble set index number is 0, that is, a user in the cell ofwhich the random access preamble set index number is 0 selects his ownrandom access preamble in the 64 cyclic shift indexes {v_(L) _(shared)⁰, v_(L) _(shared) ¹, harv_(L) _(shared) ⁶³}; the 64 cyclic shiftindexes after the set 0 is defined as a set 1, to be allocated to thecell of which the random access preamble set index number is 1, that is,the user in the cell of which the random access preamble set indexnumber is 1 selects his own random access preamble in the 64 cyclicshift indexes {v_(L) _(shared) ⁶⁴, . . . , v_(L) _(shared) ¹¹⁵, v_(L)_(shared) ₊₁ ⁰, . . . , v_(L) _(shared) ₊₁ ¹¹}; the 64 cyclic shiftindexes after the set 1 is defined as a set 2, to be allocated to thecell of which the random access preamble set index number is 2, that is,the user in the cell of which the random access preamble set indexnumber is 2 selects his own random access preamble in the 64 cyclicshift indexes {v_(L) _(shared) ₊₁ ¹², . . . , v_(L) _(shared) ₊₁ ⁷⁵};and so forth.

Accordingly, according to the random access preamble allocation methodof the embodiment of the present disclosure, from among the randomaccess preambles of each cell and the random access preamble of at leastone cell adjacent to the each cell, there at least exist a part ofrandom access preambles that are generated from the identical logicalroot sequence number, so that the part of random access preambles of theeach cell and the part of random access preambles of the at least onecell are mutually orthogonal. An interference degree between theorthogonal random access preambles is lower than an interference degreebetween the non-orthogonal random access preambles, so that the mutualinterference between the random access preambles between the adjacentcells can be reduced.

In the embodiment of the present disclosure, the number of the randomaccess preambles is set to be 64, which is not to limit the protectionscope of the present disclosure, and any predetermined number of randomaccess preambles are all possible.

FIG. 21 shows a diagram of an interference situation of a random accesspreamble among cells according to an embodiment of the presentdisclosure.

As shown in FIG. 21 , a cell C1 of a base station B1 is adjacent to acell C2 of a base station B2, a terminal a is in the cell C1, a terminalb and a terminal c are in the cell C2. According to the allocationsolution of logical root sequence numbers of the existing LTE system orNR system, the cell C1 and the cell C2 are allocated with differentlogical root sequence numbers. In consideration of reducing a systemexpense, the terminal in the two cells can transmit the random accesspreamble on the identical PRACH resource. In this case, according to aproperty of the ZC sequence, no matter what cyclic shift index isselected as the random access preamble with respect to the cells C1 andC2, it is impossible to exist a case where the random access preamble ofthe cell C1 and the random access preamble of the cell C2 areorthogonal, resulting in occurrence of the interference.

For example, when the base station B1 of the cell C1 performs adetection on the random access preamble, there may be energy from therandom access preamble of the cell C2 (for example, the random accesspreamble from the terminal b or the terminal c) overlapped on abackground interference or a ground noise of the cell C1. Since radii ofthe two cells are very small, the energy overlapped on the backgroundinterference or noise of the cell C1 may reach a degree of affecting thedetection of the terminal a on the random access preamble. In addition,the terminal of which the random access fails in the cell C2 may improvean emission power of the terminal to attempt a re-access, which may alsoaffect the detection on the random access preamble in the cell C1.

According to the embodiment of the present disclosure, assuming that therandom access preamble set 0 as shown in FIG. 20 is allocated to thecell C1, the random access preamble set 1 is allocated to the cell C2,and assuming the terminal b selects v_(L) _(shared) ⁶⁴ as the randomaccess preamble, and the terminal c selects v_(L) _(shared) ₊₁ ⁰ as therandom access preamble. In this case, since the random access preambleof the terminal b and the random access preamble of the terminal a areorthogonal, the effect on the detection for the random access preambleof the terminal a is reduced.

In the embodiment of the present disclosure, the characteristicsinvolved in the random access preamble allocation method and the randomaccess preamble determination method can be similar to those describedwith respect to the PRACH. For example, the sub-carrier spacecorresponding to the random access preamble can be lower than 1.25 KHz,which will not be repeated herein.

In this case, with reference to FIG. 21 , since the length of the randomaccess preamble is increased, the effect on the detection for the randomaccess preamble of the terminal b is also reduced.

FIG. 22 illustrates a diagram of restraining an inter-cell interferenceaccording to an embodiment of the present disclosure.

As shown in FIG. 22 , when the base station B1 uses a root ZC sequenceof which the logical root sequence number is Lshared to perform adetection, a correlation peak of the random access preamble of theterminal b will be outside of a reception window of a root sequencenumber Lshared of the cell C1, which may not affect the detection forthe random access preamble of the terminal a. Thus, the inter-cellinterference is at least partially eliminated.

In the present embodiment, when allocating the random access preamblesthrough the above manner, the random access preambles can also beimplemented according to the definition on the physical random accesschannel in the above embodiment. For example, the sub-carrier spacecorresponding to the random access preamble can be enabled to be lowerthan 1.25 KHz.

Corresponding to the random access preamble allocation method, accordingto the embodiment of the present disclosure, when the terminal performsan access operation, the available random access preamble can bedetermined according to the allocation solution of the random accesspreamble of the cell (a target cell) to which the terminal is to beaccessed.

FIG. 23 illustrates a flow diagram of a random access preambledetermination method according to an embodiment of the presentdisclosure.

The random access preamble determination method according to theembodiment of the present disclosure includes: S2310, obtaininginformation of a target cell, the information including a ZC sequencelength, a logical root sequence number, a random access preamble setindex number, and a cyclic shift interval; S2320, calculating an initiallogical root sequence number and an initial cyclic shift index accordingto the obtained information; S2330, determining an available randomaccess preamble set of the target cell according to the cyclic shiftinterval, the calculated initial logical root sequence number, and thecalculated initial cyclic shift index, wherein a random access preamblegenerated from the identical logical root sequence number exists in theavailable random access preamble set corresponding to at least twocontinuous random access preamble set index numbers.

As an example, the calculating the initial logical root sequence numberand the initial cyclic shift index according to the obtained informationincludes: calculating, according to the ZC sequence length and thecyclic shift interval, a number of random access preambles generatedfrom one logical root sequence number; calculating the initial logicalroot sequence number, according to the logical root sequence number, therandom access preamble set index number, and the calculated number ofthe random access preambles; and calculating the initial cyclic shiftindex, according to the random access preamble set index number and thecalculated number of the random access preambles.

As an example, the determining the available random access preamble setof the target cell includes: determining, according to a correspondencebetween the logical root sequence number and a physical root sequencenumber, an initial physical root sequence number corresponding to theinitial logical root sequence number; and selecting and generating,according to the initial physical root sequence number, a random accesspreamble of which a cyclic shift amount is greater than or equal to aproduct of the initial cyclic shift index and the cyclic shift intervaland of which the number is a predetermined number, wherein when thenumber of the random access preamble, of which the cyclic shift amountgenerated according to the initial physical root sequence number isgreater than or equal to the product of the initial cyclic shift indexand the cyclic shift interval, is smaller than the predetermined number,the logical root sequence number is increased by 1; in the random accesspreamble corresponding to the logical root sequence number after beingincreased by 1, the random access preamble is selected starting from therandom access preamble of which a cyclic shift index is smallest, in anorder of the cyclic shift index from small to large, to be expanded intothe random access preamble that has been selected; and operations ofincreasing the logical root sequence number by 1 and selecting therandom access preamble in the order are repeated, until the number ofthe selected random access preamble reaches the predetermined number.

For example, when a terminal in the target cell monitors a broadcastsignal of the target cell, the terminal can know through the broadcastsignal that with respect to the target call, the logical root sequencenumber is Lshared, the random access preamble set index number is N_(ID)^(preambleSet), and the cyclic shift interval is NCS.

The terminal first can calculate that the number of the random accesspreambles that can be generated by one logical root sequence number isN=└N_(ZC)/N_(CS)┘, and └⋅┘ indicates a round-down operation.Subsequently, the terminal can determine the initial logical rootsequence number of the target cell to be:

${L_{start} = {L_{shared} + \left\lfloor \frac{64 \times N_{ID}^{preambleSet}}{N} \right\rfloor}},$

and the initial cyclic shift index to be: v_(start)=(64×N_(ID)^(preambleSet))mod N, wherein └∩┘ indicates the round-down operation,and mod is a modulo operation.

In the embodiment of the present disclosure, the PRACH resource can bedesigned, configured and selected according to the design, configurationand selection method of the PRACH resource of the LTE system, the NRsystem or other communication systems. In the case where the terminalobtains the PRACH resource for transmitting the random access preamble,the available random access preamble of the terminal can be determinedaccording to the above described method, subsequently, the random accesspreamble can be selected from the available random access preamble, tobe transmitted.

All random access preambles can be generated by the zero relevant ZCsequence, and can be obtained from one or more root ZC sequences. Eachcell will broadcast the ZC sequence length N_(ZC), the logical rootsequence number L_(shared), the random access preamble set index numberN_(ID) ^(preambleSet), and the cyclic shift interval N_(CS) used by theeach cell.

In this case, the terminal can calculate the initial logical rootsequence number L_(start) and the initial cyclic shift index v_(start)of the cell according to the method in the above embodiment. Theterminal can map the initial physical root sequence number u_(start),which corresponds to the logical root sequence number L_(start) one byone, according to Table 5.7.2-4 in the protocol LTE 36.211. According tothe values of the cyclic shift interval N_(CS) and the initial cyclicshift index v_(start), all cyclic shift sequences, of which the cyclicshift amount is greater than or equal to N_(cs)×v_(start) and whichcorrespond to the initial physical root sequence number u_(start) may begenerated.

When the number of all available cyclic shift sequences of the initialphysical root sequence number u_(start) does not reach 64, the logicalroot sequence number may be increased by 1, and in all random accesspreambles corresponding to the logical root sequence number L_(start)+1,random access preambles corresponding to the smallest index aresequentially selected as extension of selectable random access preamblesof the present cell, and when the last cyclic shift of the logical rootsequence number L_(start)+1 cannot make the number of the availablerandom access preambles of the present cell reach 64, the logical rootsequence number is increased by 1 again, to continuously extend theavailable random access preambles of the present cell. And so forth, itis not stopped until the terminal can obtain all 64 available randomaccess preambles of the present cell.

In addition, the logical root sequence number of the ZC sequences iscyclic, that is, in the mapping table of the logical root sequencenumber and the physical root sequence number, the logical root sequencenumber obtained by increasing the last logical root sequence number by 1is the first logical root sequence number in the mapping table.

The 64 random access preambles are arranged according to an order offirst making the cyclic shift indexes be increased gradually and thenmaking the logical root sequence numbers be increased gradually.

FIG. 24 illustrates a diagram of grouping random access preamblesaccording to an embodiment of the present disclosure.

The 64 random access preambles are divided into three groups, as shownin FIG. 24 . The first number P of 64 random access preambles are usedfor competition-based random access, the rest number (64-P) of randomaccess preambles are used for non-competition-based random access,wherein the first number Q of random access preambles used forcompetition-based random access are called as group A, the later numbers(P-Q) are called as group B, and the purpose of such a grouping is toincrease prior information of the subsequent transmitted message 3(Msg3) of the terminal in the random access procedure. The terminalobtains values of P and Q from the system information broadcast by thecell. Similar to the existing access method, if what is performed by theterminal is a non-competition-based random access, the terminal directlyobtains a specific random access preamble from a high-layer signalingissued by the base station to the terminal itself. If what is performedby the terminal is a competition-based random access, the terminal firstneeds to determine whether to select the random access preamble from Agroup or to select the random access preamble from B group, and themanner of determining the random access preamble group is the same asthe existing method, which will not be repeated herein. After the randomaccess preamble group is determined, the terminal selects the randomaccess preamble in the determined group equiprobably and randomly. Nomatter it is allocation of the base station allocates or randomselection of the terminal, the terminal obtains the physical rootsequence number and the cyclic shift index of the random access preambleto be transmitted by the terminal itself, and the physical root sequencenumber and the cyclic shift index are marked as u and v, respectively.x_(u)(n) root ZC sequence is defined as:

${{x_{u}(n)} = {\exp\left\{ {{- j}\frac{{un}\left( {n + 1} \right)}{N_{ZC}}} \right\}}},{0 \leq n \leq {N_{ZC} - 1.}}$

Through the root ZC sequence x_(u)(n), the terminal can obtain apractically transmitted digital baseband random access preamblex_(u,v)(n)=x_(u)((n+vtN_(CS))modN_(ZC)). Experiencing IDFT and resourcemapping according to the frame structure provided in Embodiment 1, abaseband random access preamble signal can be obtained. Similar to theLTE/NR system, in the procedure of performing an up-conversion, in orderto ensure the pre guard band and post guard band of random accesspreamble are same, it is necessary to perform frequency shift of severalsub-carrier waves to a high frequency direction, and as for the randomaccess preamble structure provided in the present application, afrequency shift amount is φ·Δf_(preamble), wherein φ=8.

FIG. 25 illustrates a block diagram of a data transmission apparatus2500 according to an embodiment of the present disclosure.

As shown in FIG. 25 , the data transmission apparatus 2500 may include:a scheduling information receiving unit 2510, which receives schedulinginformation from a base station; a determining unit 2520, whichdetermines whether an allocated resource indicated by the schedulinginformation from the base station includes a resource which is at leastoverlapped with a cyclic prefix of a random access preamble or therandom access preamble; an indication information obtaining unit 2530,which obtains indication information indicating whether transmission isallowed on the overlapped resource; a data transmitting unit 2540, whichtransmits a signal on the overlapped resource, when a result of thedetermination indicates that there is the overlapped resource and theindication information indicates that the transmission is allowed on theoverlapped resource, and avoids the overlapped resource whentransmitting the signal, when the result indicates that there is theoverlapped resource and the indication information indicates that a userequipment shall avoid the overlapped resource when transmitting thesignal, wherein a sub-carrier space corresponding to the random accesspreamble is equal to or smaller than 1 KHz, and the cyclic prefix of therandom access preamble or the random access preamble is located in atransmission time interval prior to the transmission time interval wherethe random access preamble is located.

The the data transmission apparatus 2500 may correspond to the terminaldevice.

FIG. 26 illustrates a block diagram of a random access preambleallocation apparatus 2600 according to an embodiment of the presentdisclosure.

As shown in FIG. 26 , the random access preamble allocation apparatus2600 may include: an interference strength determining unit 2610, whichdetermines whether an interference strength between adjacent cells isgreater than a strength threshold; and an index number allocating unit2620, which allocates, for each of the adjacent cells, an identical ZCsequence length, an identical cyclic shift interval, an identicallogical root sequence number, and different and continuous random accesspreamble set index numbers, when the interference strength is greaterthan the strength threshold, wherein the ZC sequence length, the cyclicshift interval, the logical root sequence number, and the random accesspreamble set index number are configured to determine an availablerandom access preamble set of the each of the adjacent cells, andwherein the random access preamble generated from the identical logicalroot sequence number exists in the available random access preamble setcorresponding to at least two continuous random access preamble setindex numbers.

As an example, a sub-carrier space corresponding to the random accesspreamble is lower than 1.25 KHz.

As an example, the sub-carrier space is equal to 1 KHz, and a pre guardperiod of the random access preamble and a cyclic prefix of the randomaccess preamble are located in a transmission time interval prior to thetransmission time interval where the random access preamble is located.

As an example, the sub-carrier space is higher than 1 KHz and lower than1.25 KHz, and a sum of lengths of following items is 1 ms: a pre guardperiod of the random access preamble, a cyclic prefix of the randomaccess preamble, the random access preamble, and a post guard period ofthe random access preamble.

As an example, the post guard period is zero, and a cyclic prefix of afirst OFDM symbol in a transmission time interval subsequent to thetransmission time interval, where the random access preamble is located,functions as the post guard period of the random access preamble, or,the length of the pre guard period is equal to the length of the cyclicprefix of the random access preamble, and a difference between a sum oflengths, which include the length of the post guard period and a lengthof the cyclic prefix of the first OFDM symbol of the subsequenttransmission time interval, and the length of the cyclic prefix of therandom access preamble is smaller than or equal to 2Ts, or, the lengthof the pre guard period is zero, and a difference between the length ofthe post guard period and the length of the cyclic prefix of the randomaccess preamble is smaller than or equal to 2Ts.

The random access preamble allocation apparatus 2600 may correspond tothe terminal device, the base station, network entity or other device.

FIG. 27 illustrates a block diagram of a random access preambledetermination apparatus 2700 according to an embodiment of the presentdisclosure.

As shown in FIG. 27 , the random access preamble determination apparatus2700 may include: an information obtaining unit 2710, which obtainsinformation of a target cell, the information including a ZC sequencelength, a logical root sequence number, a random access preamble setindex number, and a the cyclic shift interval; a calculating unit 2720,which calculates an initial logical root sequence number and an initialcyclic shift index according to the obtained information; and a randomaccess preamble set determining unit 2730, which determines an availablerandom access preamble set of the target cell according to the cyclicshift interval, the calculated initial logical root sequence number, andthe calculated initial cyclic shift index.

As an example, the calculating unit 2720 is configured to: calculate,according to the ZC sequence length and the cyclic shift interval, anumber of random access preambles generated from one logical rootsequence number; calculate the initial logical root sequence number,according to the logical root sequence number, the random accesspreamble set index number, and the calculated number of the randomaccess preambles; and calculate the initial cyclic shift index,according to the random access preamble set index number and thecalculated number of the random access preambles.

As an example, the random access preamble set determining unit 2730 isconfigured to: determine, according to a correspondence between thelogical root sequence number and a physical root sequence number, aninitial physical root sequence number corresponding to the initiallogical root sequence number; and select and generate, according to theinitial physical root sequence number, a random access preamble of whicha cyclic shift amount is greater than or equal to a product of theinitial cyclic shift index and the cyclic shift interval and of whichthe number is a predetermined number, wherein when the number of therandom access preamble, of which the cyclic shift amount generatedaccording to the initial physical root sequence number is greater thanor equal to the product of the initial cyclic shift index and the cyclicshift interval, is smaller than the predetermined number, the logicalroot sequence number is increased by 1; in the random access preamblecorresponding to the logical root sequence number after being increasedby 1, the random access preamble is selected starting from the randomaccess preamble of which a cyclic shift index is smallest, in an orderof the cyclic shift index from small to large, to be expanded into therandom access preamble that has been selected; and operations ofincreasing the logical root sequence number by 1 and selecting therandom access preamble in the order are repeated, until the number ofthe selected random access preamble reaches the predetermined number.

The random access preamble determination apparatus 2700 may correspondto the terminal device, the base station, network entity or otherdevice.

The embodiment of the present disclosure designs a time domain structureof the PRACH resource with respect to a full-duplex cell. Through amanner of increasing the length of the random access preamble, adetection ability of the random access preamble is improved, and therandom access preambles are allocated by sharing the logical rootsequence number, to improve the number of the orthogonal random accesspreambles. On one hand, the mutual interference between the randomaccess preambles of different terminals in the present cell can bereduced, and on the other hand, the ability against the interference ofthe downlink signals of the present cell and the adjacent cell on therandom access preamble is also improved, so that the mutual interferenceon the random access preambles between the adjacent cells is reduced oreven totally eliminated.

According to another embodiment of the present disclosure, there isprovided a computer readable storage medium stored with a computerprogram, wherein when the computer program is performed by a processor,the above described method is implemented.

According to another embodiment of the present disclosure, there isprovided an electronic apparatus, wherein the electronic apparatusincludes: a processor; and a storage stored therein a computer program,wherein when the computer program is performed by a processor, the abovedescribed method is implemented.

The program running on the device according to the present disclosuremay be a program that causes a computer to implement the functions ofthe embodiments of the present disclosure by controlling a centralprocessing unit (CPU). The program or information processed by theprogram may be temporarily stored in volatile memory (such as randomaccess memory RAM), hard disk drive (HDD), non-volatile memory (such asflash memory), or other memory systems.

Computer-executable instructions or programs for implementing thefunctions of various embodiments of the present disclosure may berecorded on a computer-readable storage medium. Corresponding functionscan be realized by having a computer system read programs recorded onthe recording medium and execute these programs. The so-called “computersystem” herein may be a computer system embedded in the device, and mayinclude an operating system or hardware (such as a peripheral device).The “computer-readable storage medium” may be a semiconductor recordingmedium, an optical recording medium, a magnetic recording medium, ashort-time dynamic storage program recording medium, or any otherrecording media readable by a computer.

Various features or functional modules of the devices used in the aboveembodiments may be implemented or performed by circuitry (e.g., asingle-chip or multi-chip integrated circuit). Circuits designed toperform the functions described in the present specification may includegeneral purpose processors, digital signal processors (DSPs),application specific integrated circuits (ASICs), field programmablegate arrays (FPGAs), or other programmable logic devices, discrete Gateor transistor logic, discrete hardware components, or any combination ofthe above. A general-purpose processor may be a microprocessor or anyexisting processor, controller, microcontroller, or state machine. Theabove circuit may be a digital circuit or an analog circuit. In a caseof new integrated circuit technology that replaces existing integratedcircuits due to advances in semiconductor technology, one or moreembodiments of the present disclosure may also be implemented usingthese new integrated circuit technologies.

FIG. 28 illustrates a terminal device according to embodiments of thepresent disclosure.

Referring to the FIG. 28 , the terminal device 2800 may include aprocessor 2810, a transceiver 2820 and a memory 2830. However, all ofthe illustrated components are not essential. The terminal device 2800may be implemented by more or less components than those illustrated inFIG. 28 . In addition, the processor 2810 and the transceiver 2820 andthe memory 2830 may be implemented as a single chip according to anotherembodiment.

The terminal device 2800 may correspond to the terminal device 1100 ofFIG. 11 . Also, the processor 2810 may correspond to the processor 1101and the memory 2830 may correspond to the memory 1102.

The terminal device 2800 may correspond to the data transmittingapparatus 2500. The terminal device 2800 may correspond to the randomaccess preamble allocation apparatus 2600. The terminal device 2800 maycorrespond to the random access preamble determining apparatus 2700.

The aforementioned components will now be described in detail.

The processor 2810 may include one or more processors or otherprocessing devices that control the proposed function, process, and/ormethod. Operation of the UE 2800 may be implemented by the processor2810.

The transceiver 2820 may include a RF transmitter for up-converting andamplifying a transmitted signal, and a RF receiver for down-converting afrequency of a received signal. However, according to anotherembodiment, the transceiver 2820 may be implemented by more or lesscomponents than those illustrated in components.

The transceiver 2820 may be connected to the processor 2810 and transmitand/or receive a signal. The signal may include control information anddata. In addition, the transceiver 2820 may receive the signal through awireless channel and output the signal to the processor 2810. Thetransceiver 2820 may transmit a signal output from the processor 2810through the wireless channel.

The memory 2830 may store the control information or the data includedin a signal obtained by the UE 2800. The memory 2830 may be connected tothe processor 2810 and store at least one instruction or a protocol or aparameter for the proposed function, process, and/or method. The memory2830 may include read-only memory (ROM) and/or random access memory(RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storagedevices.

In an embodiment, the processor 2810 configured to receivetime-frequency resource configuration information from a base station,which the time-frequency resource configuration information includesconfiguration information of measurement time-frequency resources formeasuring the cross-link interference, determine the measurementtime-frequency resources for measuring the cross-link interferenceaccording to the time-frequency resource configuration information,measure the cross-link interference on the measurement time-frequencyresources and feed back a measurement result of the cross-linkinterference to the base station.

FIG. 29 schematically illustrates a base station according toembodiments of the present disclosure.

Referring to the FIG. 29 , the base station 2900 may include a processor2910, a transceiver 2920 and a memory 2930. However, all of theillustrated components are not essential. The base station 2900 may beimplemented by more or less components than those illustrated in FIG. 29. In addition, the processor 2910 and the transceiver 2920 and thememory 2930 may be implemented as a single chip according to anotherembodiment.

The base station 2900 may correspond to the base station 1200 of FIG. 12. Also, the processor 2910 may correspond to the processor 1201 and thememory 2930 may correspond to the memory 1202.

The base station 2900 may correspond to random access preambleallocation apparatus 2600. The base station 2900 may correspond to therandom access preamble determination apparatus 2700.

The aforementioned components will now be described in detail.

The processor 2910 may include one or more processors or otherprocessing devices that control the proposed function, process, and/ormethod. Operation of the base station 2900 may be implemented by theprocessor 2910.

The transceiver 2920 may include a RF transmitter for up-converting andamplifying a transmitted signal, and a RF receiver for down-converting afrequency of a received signal. However, according to anotherembodiment, the transceiver 2920 may be implemented by more or lesscomponents than those illustrated in components.

The transceiver 2920 may be connected to the processor 2910 and transmitand/or receive a signal. The signal may include control information anddata. In addition, the transceiver 2920 may receive the signal through awireless channel and output the signal to the processor 2910. Thetransceiver 2920 may transmit a signal output from the processor 2910through the wireless channel.

The memory 2930 may store the control information or the data includedin a signal obtained by the base station 2900. The memory 2930 may beconnected to the processor 2910 and store at least one instruction or aprotocol or a parameter for the proposed function, process, and/ormethod. The memory 2930 may include read-only memory (ROM) and/or randomaccess memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/orother storage devices.

In an embodiment, the processor 2910 configured to configuretime-frequency resources for a terminal device, which the time-frequencyresources comprise measurement time-frequency resources for measuringthe cross-link interference, transmit time-frequency resourceconfiguration information to the terminal device, receive, from theterminal device, a measurement result of cross-link interferencemeasured by the terminal device on measurement time-frequency resourcesfor measuring the cross-link interference determined according to thetime-frequency resource configuration information and schedule theterminal device according to the measurement result.

Although the present disclosure has been described with an embodiment,various changes and modifications may be suggested to one skilled in theart. It is intended that the present disclosure encompass such changesand modifications as fall within the scope of the appended claims.

The embodiments of the present disclosure have been described in detailabove with reference to the drawings. However, the specific structure isnot limited to the above-mentioned embodiments, and the presentdisclosure also includes any design changes without departing from thespirit of the present disclosure. In addition, various modifications canbe made to the present disclosure within the scope of the claims, andthe embodiments obtained by appropriately combining the technical meansdisclosed in different embodiments are also included in the technicalscope of the present disclosure. In addition, components having the sameeffects described in the above embodiments may be replaced with eachother.

Although the present disclosure has been described with variousembodiments, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed is:
 1. A method performed by a user equipment (UE) in awireless communication system, the method comprising: identifying randomaccess preamble related information with respect to a first cell; andtransmitting, to a base station (BS), a random access preamble via aphysical random access channel (PRACH) based on the random accesspreamble related information, wherein the random access preamble relatedinformation include a first value related to the random access preamblefor the first cell, and wherein the first value related to the randomaccess preamble is a same value with a first value to the random accesspreamble for a second cell.
 2. The method of claim 1, wherein the randomaccess preamble related information with respect to the first cell isreceived by the BS, wherein the information related to the random accesspreamble includes at least one of a zadoff-chu (ZC) sequence length forthe first cell, a cyclic shift interval for the first cell, a logicalroot sequence number for the first cell, or a random access preamble setindex number with respect to the first cell, and wherein the first valuerelated to the random access preamble corresponds to at least one of theZC sequence length for the first cell, the cyclic shift interval for thefirst cell, or the logical root sequence number for the first cell. 3.The method of claim 1, wherein the random access preamble is identifiedbased on at least one cyclic shift index corresponding to a first randomaccess preamble set index number with respect to the first cell, whereina random access preamble set index number with respect to the first cellis a different value with a random access preamble set index number withrespect to the second cell, and wherein the at least one cyclic shiftindex is identified based on the random access preamble relatedinformation with respect to the first cell.
 4. The method of claim 1,wherein the random access preamble related information with respect tothe first cell is identified based on an interference strength betweenthe first cell and the second cell and a strength threshold.
 5. Themethod of claim 1, further comprising: receiving, from the BS, a messageincluding a first value corresponding to a number of random accesspreambles for contention-based random access and a second valuecorresponding to a number of random access preambles forcontention-based random access.
 6. The method of claim 1, furthercomprising: receiving, from the BS, information indicating whether datais available to being transmitted or received on an allocated resource,wherein the allocated resource is a resource overlapping with a resourcerelated to the random access preamble, and wherein the informationindicating whether the data is available to being transmitted orreceived on the allocated resource is received by at least one ofdownlink control information, a radio resource control (RRC) message, ora system information message.
 7. The method of claim 1, wherein thePRACH includes at least one of a pre guard period, cyclic prefix of therandom access preamble, or a post guard period, and wherein asub-carrier space corresponding to the random access preamble is higherthan or equal to 1 KHz and lower than or equal to 1.25 KHz.
 8. A methodperformed by a base station (BS) in a wireless communication system, themethod comprising: identifying random access preamble relatedinformation with respect to a first cell; and receiving, from a userequipment (UE), a random access preamble via a physical random accesschannel (PRACH) based on the random access preamble related information,wherein the random access preamble related information include a firstvalue related to the random access preamble for the first cell, andwherein the first value related to the random access preamble is a samevalue with a first value to the random access preamble for a secondcell.
 9. The method of claim 8, wherein the random access preamblerelated information with respect to the first cell is transmitted to theUE, wherein the information related to the random access preambleincludes at least one of a zadoff-chu (ZC) sequence length for the firstcell, a cyclic shift interval for the first cell, a logical rootsequence number for the first cell, or a random access preamble setindex number with respect to the first cell, and wherein the first valuerelated to the random access preamble corresponds to at least one of theZC sequence length for the first cell, the cyclic shift interval for thefirst cell, or the logical root sequence number for the first cell. 10.The method of claim 8, wherein the random access preamble is identifiedbased on at least one cyclic shift index corresponding to a first randomaccess preamble set index number with respect to the first cell, whereina random access preamble set index number with respect to the first cellis a different value with a random access preamble set index number withrespect to the second cell, and wherein the at least one cyclic shiftindex is identified based on the random access preamble relatedinformation with respect to the first cell.
 11. The method of claim 8,wherein the random access preamble related information with respect tothe first cell is identified based on an interference strength betweenthe first cell and the second cell and a strength threshold.
 12. Themethod of claim 8, further comprising: transmitting, to the UE, amessage including a first value corresponding to a number of randomaccess preambles for contention-based random access and a second valuecorresponding to a number of random access preambles forcontention-based random access.
 13. The method of claim 8, furthercomprising: transmitting, to the UE, information indicating whether datais available to being transmitted or received on an allocated resource,wherein the allocated resource is a resource overlapping with a resourcerelated to the random access preamble, and wherein the informationindicating whether the data is available to being transmitted orreceived on the allocated resource is transmitted by at least one ofdownlink control information, a radio resource control (RRC) message, ora system information message.
 14. The method of claim 8, wherein thePRACH includes at least one of a pre guard period, cyclic prefix of therandom access preamble, or a post guard period, and wherein asub-carrier space corresponding to the random access preamble is higherthan or equal to 1 KHz and lower than or equal to 1.25 KHz.
 15. A userequipment (UE) performed in a wireless communication system, the UEcomprising: a transceiver; and at least one processor coupled to thetransceiver and configured to: identify random access preamble relatedinformation with respect to a first cell, and transmit, to a basestation (BS), a random access preamble via a physical random accesschannel (PRACH) based on the random access preamble related information,wherein the random access preamble related information include a firstvalue related to the random access preamble for the first cell, andwherein the first value related to the random access preamble is a samevalue with a first value to the random access preamble for a secondcell.
 16. The UE of claim 15, wherein the random access preamble relatedinformation with respect to the first cell is received by the BS,wherein the information related to the random access preamble includesat least one of a zadoff-chu (ZC) sequence length for the first cell, acyclic shift interval for the first cell, a logical root sequence numberfor the first cell, or a random access preamble set index number withrespect to the first cell, and wherein the first value related to therandom access preamble corresponds to at least one of the ZC sequencelength for the first cell, the cyclic shift interval for the first cell,or the logical root sequence number for the first cell.
 17. The UE ofclaim 15, wherein the random access preamble is identified based on atleast one cyclic shift index corresponding to a first random accesspreamble set index number with respect to the first cell, wherein arandom access preamble set index number with respect to the first cellis a different value with a random access preamble set index number withrespect to the second cell, and wherein the at least one cyclic shiftindex is identified based on the random access preamble relatedinformation with respect to the first cell.
 18. The UE of claim 15,wherein the random access preamble related information with respect tothe first cell is identified based on an interference strength betweenthe first cell and the second cell and a strength threshold.
 19. The UEof claim 15, wherein the at least one processor is further configuredto: receive, from the BS, a message including a first valuecorresponding to a number of random access preambles forcontention-based random access and a second value corresponding to anumber of random access preambles for contention-based random access.20. The UE of claim 15, wherein the at least one processor is furtherconfigured to: receive, from the BS, information indicating whether datais available to being transmitted or received on an allocated resource,wherein the allocated resource is a resource overlapping with a resourcerelated to the random access preamble, and wherein the informationindicating whether the data is available to being transmitted orreceived on the allocated resource is received by at least one ofdownlink control information, a radio resource control (RRC) message, ora system information message.